Ukrainian President Volodymyr Zelensky used the anniversary to accuse Moscow of endangering global nuclear safety, saying repeated Russian drone operations near the Chernobyl nuclear power plant risked triggering another man-made catastrophe.

“Russia is once again bringing the world to the brink of a man-made disaster,” Zelensky wrote on social media, referring to Iranian-designed Shahed drones used extensively by Russian forces since the full-scale invasion began in February 2022.

He said such drones had repeatedly flown over the plant and that one had struck the protective confinement structure last year, calling for stronger international pressure to halt what he described as “nuclear terrorism.”Russian missile and drone strikes on the southeastern Ukrainian city of Dnipro killed at least nine people, regional officials said, making it the deadliest single attack reported during the latest wave of cross-border strikes.

In Russian-occupied Crimea, Moscow-installed authorities said one man was killed in a Ukrainian drone strike on the port city of Sevastopol. Russia annexed Crimea from Ukraine in 2014, a move widely rejected by the international community, and has since used the peninsula as a key military logistics hub.

In eastern Ukraine’s occupied Luhansk region, Leonid Pasechnik, the Russia-backed governor, said three people were killed in an overnight Ukrainian drone strike on a village, after earlier reporting two deaths on Saturday.Earlier, authorities in Russia’s Belgorod border region said a woman was killed in a Ukrainian drone attack.

Ukraine did not publicly comment on the strikes in Crimea or Luhansk, and the claims could not be independently verified.Ukraine’s military said it had also struck an oil refinery in Yaroslavl, deep inside Russian territory, triggering fires at a facility that processes around 15 million tons of oil annually and produces gasoline, diesel and jet fuel, including supplies for the Russian military.Russia did not immediately comment on the refinery attack.

Kyiv has increasingly used domestically developed long-range drones capable of reaching targets up to 1,500 km (900 miles) inside Russia, targeting energy infrastructure and military logistics sites.Ukrainian officials argue such strikes are aimed at reducing Russian military capacity, particularly as Moscow seeks to increase oil exports after the Trump administration granted temporary sanctions waivers to ease global supply constraints.

The anniversary of the 1986 Chernobyl disaster also renewed focus on the safety of the damaged reactor site.Rafael Grossi, director general of the International Atomic Energy Agency, said repairs to the plant’s outer protective shell must begin urgently after damage from a strike last year compromised a key safety function of the structure.

He warned that prolonged delays could increase risks to the original sarcophagus covering Reactor No. 4, the site of the world’s worst nuclear disaster.The European Bank for Reconstruction and Development estimated repairs would require at least 500 million euros ($586 million).

Ukraine’s Energy Minister Denys Shmyhal said international partners had so far committed 100 million euros in additional funding, on top of a previously agreed 30 million euros.Ukrainian officials say a Russian drone struck the outer shell of the New Safe Confinement structure in February 2025.

The $2.1 billion steel arch, completed in 2019, was built to contain radioactive material over the destroyed reactor.Moscow denied responsibility and accused Kyiv of staging the incident.Separately, Russia’s Defense Minister Andrei Belousov visited North Korea on Sunday for talks with leader Kim Jong Un, where both sides discussed expanding military cooperation.

Belousov said the two countries had agreed to move military ties to a “sustainable, long-term basis,” according to Russian state news agency RIA Novosti.During the visit, he awarded Russia’s Order of Courage to North Korean troops who served in Russia’s Kursk region, where Ukrainian forces launched a surprise incursion in August 2024.

Kim has supplied thousands of troops and significant weapons shipments to support Russia’s war effort.

The visit comes as Moscow and Pyongyang continue to strengthen military and diplomatic cooperation following their 2024 strategic defence pact.Earlier, North Korean state media KCNA reported that Russian State Duma Chairman Vyacheslav Volodin had also arrived in Pyongyang to attend the opening ceremony of a newly built memorial honoring North Korean troops killed while fighting in the Ukraine war.

Belousov is expected to hold meetings with North Korea’s top leadership and participate in “ceremonial and commemorative events,” according to the Russian defence ministry.Separately, the Kremlin said Russian President Vladimir Putin sent a telegram to North Korean leader Kim Jong Un marking the opening of the memorial.

Putin thanked Kim and North Korean soldiers for assisting Russia in repelling what Moscow described as a major Ukrainian incursion into the western Kursk region and said he was confident the two countries would continue strengthening their strategic partnership.

Russia and North Korea significantly expanded their relations after Kim and Putin met in June 2024 and signed a comprehensive strategic treaty that included a mutual defence clause.Since 2023, both countries have accelerated military exchanges and diplomatic coordination, drawing close international scrutiny over North Korea’s alleged military support for Russia’s war effort in Ukraine.

The memorial inauguration and Belousov’s visit underscore the growing public acknowledgment of North Korea’s role in the conflict and signal further institutional deepening of Moscow-Pyongyang security ties.