In a readout issued by Downing Street, a spokesperson said the two leaders discussed the failed negotiations held in Pakistan over the weekend and agreed it was “vital” to maintain the ceasefire while seeking a path forward through dialogue.

Starmer, who recently returned from meetings in the Middle East, also said international partners were working to restore safe navigation through the Strait of Hormuz, a key global energy transit route, and reaffirmed Britain’s commitment to Oman’s security.

UK Health Secretary Wes Streeting described the breakdown in talks as “disappointing,” while emphasizing that continued engagement remained necessary to achieve a sustainable end to the conflict.

Speaking to Sky News, he said diplomacy often requires persistence, adding that lack of immediate success did not diminish the value of ongoing negotiations.

Streeting also criticized comments made earlier by U.S. President Donald Trump during the crisis, calling them “extraordinary,” particularly remarks he said appeared to threaten Iranian civilization.

Separately, Australian Foreign Minister Penny Wong called for the continuation of the Middle East ceasefire and a return to negotiations, stating that the outcome of the Islamabad talks was disappointing but underscoring the need for further diplomatic efforts.

The statements come after high-level U.S.-Iran talks ended without agreement, prolonging uncertainty over a conflict that has disrupted regional stability and global energy markets.

Iran has rejected a U.S. ultimatum to reopen the Strait of Hormuz by a deadline set by former U.S. President Donald Trump, as military strikes intensified and diplomatic efforts led by Pakistan approached what officials described as a critical stage.

With hours remaining before the deadline, a senior Iranian source said Tehran would not reopen the strategic waterway without concessions from Washington that had not been offered. The Strait of Hormuz, a key global energy corridor, has effectively been closed by Iran to most international shipping since late February following joint U.S.-Israeli military actions.

Trump warned that failure to comply would result in large-scale destruction of Iranian infrastructure, including power grids and bridges. In a social media post, he stated that “a whole civilization will die tonight,” framing the moment as a pivotal point in global history.

The remarks drew criticism from legal experts, including a former U.S. State Department adviser now with the International Crisis Group, who said the language could be interpreted as a threat violating international norms.

Military activity escalated across Iran throughout the day. Strikes were reported on transport infrastructure, including railway and highway bridges, as well as an airport and a petrochemical facility. U.S. forces also targeted installations on Kharg Island, which hosts Iran’s primary oil export terminal.

Power outages were reported in parts of Karaj following damage to transmission lines and a substation.Iran signalled a broadening of its response. Officials warned that Gulf states aligned with Washington could face retaliatory strikes on critical infrastructure.

A senior Iranian source said such actions could disrupt electricity and water supplies in desert cities dependent on energy systems.Iran’s Revolutionary Guards issued a statement saying previous restraint had ended and that Tehran would seek to deprive the United States and its regional allies of oil and gas resources.

Iranian authorities also claimed responsibility for attacks on a vessel in the Gulf and on a major Saudi petrochemical facility in Jubail, where international energy companies operate.In parallel, reports emerged of an overnight strike on a synagogue in Tehran, which Iranian officials attributed to Israeli forces.

Footage aired by state media showed debris scattered across the site, including religious texts. Israel’s military did not immediately comment on the incident.Diplomatic efforts led by Pakistan continued amid the escalation.

Iranian officials said mediation attempts were “approaching a critical, sensitive stage,” with Islamabad relaying messages between the two sides. A proposal under discussion included a temporary ceasefire and partial reopening of the strait, with broader negotiations to follow.

However, Iranian sources said Tehran had rejected interim arrangements, insisting instead on a permanent cessation of hostilities, guarantees against future attacks and compensation for damage.Iran’s conditions, as outlined through official channels, also included maintaining control over the strait and introducing a mechanism to regulate transit, potentially involving fees.

Prior to the conflict, the waterway functioned as an open international route through which roughly one-fifth of global oil and liquefied natural gas supplies passed.Despite the intensifying conflict, global markets showed limited reaction, reflecting uncertainty over whether the U.S. would carry out the threatened escalation.

Trump has previously issued similar warnings but later stepped back, citing unspecified progress in talks, claims that Iranian officials have denied.On the ground, residents expressed concern over the prospect of further escalation.

A resident in Isfahan said she hoped the latest threats would not materialise, reflecting broader public anxiety as military actions continued.Iran maintains that any negotiations must follow a halt to U.S. and Israeli strikes and include the lifting of sanctions.

Without such measures, officials indicated that Tehran would continue its current posture, including restrictions on maritime transit through the Strait of Hormuz.

As the deadline approached, neither side signalled a willingness to compromise, raising the risk of further escalation in a conflict that has already disrupted regional stability and global energy flows.

Ishaq Dar said after meetings with regional counterparts that Islamabad was ready to facilitate “meaningful talks” toward a “comprehensive and lasting settlement,” including potential U.S.-Iran negotiations. It was not immediately clear whether either side had agreed to participate.

Iran’s parliament speaker Mohammad Baqer Qalibaf accused Washington of signalling openness to diplomacy while preparing for military escalation, saying Tehran would not accept demands amounting to surrender.U.S. officials have not publicly confirmed any agreement to attend talks.

Reports cited by U.S. media indicate the Pentagon is assessing options that could include ground operations, though no final decision has been announced by Donald Trump.

Discussions among regional powers, including Saudi Arabia, Turkey and Egypt, have focused on reopening the Strait of Hormuz, where Iranian restrictions on shipping since late February have disrupted global oil flows.

The conflict has driven oil prices sharply higher and intensified risks to maritime trade, with additional threats emerging near the Bab el-Mandeb Strait following attacks by Iran-aligned Houthi forces.

Israel said it carried out more than 140 air strikes across Iran over a 24-hour period, targeting missile infrastructure and other sites. Iranian media reported damage to Mehrabad airport in Tehran and a petrochemical facility in Tabriz.

Missile and drone exchanges have extended beyond Iran, with strikes reported in southern Israel near Beersheba and damage to industrial facilities in Gulf states including the United Arab Emirates and Bahrain.

The International Atomic Energy Agency said Iran’s heavy water production plant at Khondab had suffered severe damage and was no longer operational, though it contained no declared nuclear material.

The U.S. military has begun deploying thousands of Marines to the region, with the first contingent arriving aboard an amphibious assault ship, according to official statements.

Washington last week proposed a ceasefire framework that included reopening Hormuz and limiting Iran’s nuclear programme, but Tehran rejected the plan.

The conflict has triggered domestic political divisions in the United States, with protests reported in multiple cities and lawmakers offering sharply differing views on the war’s trajectory.

The move came as markets reacted to continuing uncertainty surrounding the regional conflict, with Iran warning that Washington would “bitterly regret” the sinking of an Iranian warship off Sri Lanka.The U.S. Dollar Index, which tracks the greenback against a basket of six major currencies, was last up 0.11% at 98.91 in trading across European and Asian markets.Safe-haven demand returnsThe dollar’s advance reflects renewed investor caution as geopolitical risks intensify across the Middle East. Market participants had briefly hoped for signs of de-escalation earlier this week, but those expectations faded after fresh developments raised the prospect of a broader conflict.Heightened geopolitical uncertainty often leads investors to move capital into assets perceived as safer during periods of volatility, including the U.S. dollar and government bonds.Currency markets have reacted quickly to developments linked to the conflict, with traders adjusting positions in response to each new headline.

Markets react to geopolitical uncertaintyAnalysts said the unpredictable nature of the situation has made investors particularly sensitive to news related to the conflict.“Everyone is fumbling around in the dark,” said Nick Rees, head of macro research at Monex.“Most investors recognise that they do not have a high level of confidence when it comes to the outlook over these tensions, and it is leaving markets highly reactive to even small headline developments,” Rees said.The cautious sentiment has contributed to fluctuations across global currency markets, with traders seeking clarity about how the conflict could evolve and affect broader financial conditions.

Geopolitics drives currency movesThe dollar had recently climbed to three-month highs as geopolitical tensions intensified, reflecting sustained demand for the currency during periods of global uncertainty.Investors continue to monitor developments in the Middle East closely, particularly signals that could influence energy markets and global economic stability.Currency traders said that ongoing geopolitical risks and shifting market expectations are likely to keep exchange-rate movements volatile as investors respond to developments in the conflict and assess the broader implications for global financial markets.

Speaking in Moscow, Kremlin spokesperson Dmitry Peskov stated that diplomatic options had not yet been fully explored in the standoff involving Iran and the United States. He urged all parties to avoid military action and instead focus on dialogue to prevent further escalation.

Peskov stressed that the situation requires careful handling, noting that any resort to force could have serious and far-reaching consequences. According to him, military action would not resolve disputes but instead create chaos and increase instability across the Middle East.

The comments come after renewed warnings from US President Donald Trump, who said Washington was prepared to launch military strikes against Iran if it deemed them necessary. Such statements have heightened tensions at a time when regional security remains under strain due to multiple ongoing conflicts.

Russia, which maintains close ties with Tehran, has consistently called for diplomatic solutions to disputes involving Iran. Moscow views dialogue as the most effective way to address disagreements over security, sanctions, and regional influence.

The Kremlin’s position reflects broader concerns about the potential fallout of military confrontation in the region. Officials fear that any escalation could trigger a chain reaction involving multiple countries and armed groups.

Iran, for its part, has issued strong warnings in response to US threats. Tehran’s leadership has made it clear that it would respond forcefully to any attack on its territory or interests.

Iranian Foreign Minister Abbas Araghchi said the country’s forces were on high alert and prepared to react decisively. His remarks underscore the seriousness with which Tehran views the possibility of military action by Washington.

The current standoff also takes place against the backdrop of Iran’s internal unrest and international criticism of its domestic policies. Rights organizations have accused Iranian security forces of using excessive force during crackdowns on protests, resulting in thousands of deaths.

These allegations have further strained Iran’s relations with Western countries and added another layer of complexity to diplomatic efforts. The United States has cited human rights concerns as part of its broader criticism of Tehran.

Russia has emerged as one of Iran’s key allies in recent years, particularly during the conflict in Ukraine. Tehran’s support has strengthened bilateral ties and deepened strategic cooperation between the two countries.

Moscow’s call for restraint reflects its interest in preventing a wider regional conflict that could affect its own strategic priorities. Stability in the Middle East remains important for Russia’s diplomatic, economic, and security interests.

Analysts say Russia is likely to continue positioning itself as a mediator, advocating negotiations while opposing unilateral military action. Such a role allows Moscow to maintain influence in regional affairs while reinforcing its image as a proponent of diplomacy.

The Kremlin’s remarks suggest that Russia believes there is still time for talks to de-escalate tensions. Officials argue that diplomatic channels should remain open, even amid harsh rhetoric and mutual threats.

As the situation evolves, international attention remains focused on whether dialogue can prevail over confrontation. The coming weeks may prove critical in determining whether negotiations can ease tensions or whether the crisis will deepen.

The situation has intensified following strong rhetoric from both sides and the expected deployment of additional US military assets to the region.

Air travel disruptions have become more visible in recent days, with multiple international carriers adjusting flight paths, suspending services, or extending travel times due to restricted airspace.

Aviation authorities in Europe and elsewhere have advised airlines to avoid certain zones, particularly over Iran and neighbouring countries, as uncertainty continues to grow.

Several airlines have confirmed that they are closely monitoring developments and responding in real time to the evolving security environment

These decisions are based on risk assessments that consider military movements, diplomatic signals, and the potential for sudden escalation affecting civilian aviation routes.

Dutch carrier KLM has announced that it will avoid flying through the airspace of Iran, Iraq, Israel, and several Gulf countries until further notice.

The airline stated that this move is purely precautionary and reflects its commitment to operational safety amid heightened geopolitical risks in the region.

Air France has taken a slightly different approach by resuming its Dubai service after a brief suspension, while confirming that it continues to evaluate conditions continuously.

The airline emphasised that flight operations are subject to change depending on security assessments and guidance from international aviation bodies.

Germany’s Lufthansa has also implemented strict measures, choosing to bypass Iranian and Iraqi airspace and limiting certain regional routes to daytime operations only.

The airline acknowledged that these restrictions could result in flight cancellations or delays but prioritised passenger safety over schedule certainty.

British Airways temporarily suspended flights to Bahrain earlier in the month as a precaution, though services have since resumed.

The airline stated that it remains vigilant and will continue to review the situation closely, highlighting that decisions may change quickly if conditions deteriorate.

Finnair has confirmed that it no longer flies through Iraqi airspace and has rerouted flights to destinations such as Doha and Dubai via alternative paths, including over Saudi Arabia.

The airline had already been avoiding Iranian, Syrian, and Israeli airspace due to longstanding security considerations.

Low-cost carrier Wizz Air has also adjusted operations, avoiding both Iranian and Iraqi airspace.

As a result, some westbound flights from Gulf airports now require refuelling and crew-change stops in European cities, increasing overall travel time for passengers.

Aviation analysts note that such rerouting increases fuel consumption, operational costs, and flight durations, which may eventually impact ticket prices if tensions persist. However, airlines have stressed that safety remains the overriding factor guiding these decisions.

Passengers travelling to or from the Middle East are being advised to check flight statuses regularly and allow extra time for journeys, as further changes remain possible.

With diplomatic signals still uncertain, airlines are expected to maintain a cautious stance in the coming weeks.