Willie Walsh, director general of the International Air Transport Association, told reporters in Singapore that while crude prices had fallen below $100 per barrel following a U.S.-Iran ceasefire announcement, jet fuel costs were likely to remain elevated due to constraints on refining output.

“If it were to reopen and remain open, I think it will still take a period of months to get back to where supply needs to be given the disruption to the refining capacity in the Middle East,” Walsh said, adding that the region is critical to global supply of refined products beyond aviation fuel.

The Strait of Hormuz, which carries about a fifth of the world’s oil trade, has been heavily disrupted during the recent conflict, squeezing fuel availability and driving up costs across the aviation sector.

Airlines in Asia have responded by cutting flights, carrying additional fuel from origin airports and adding refueling stops, measures that have increased operational costs for carriers already dealing with a sharp rise in jet fuel prices.

The impact has been most acute in import-dependent markets such as Vietnam, Myanmar and Pakistan, where supply constraints have tightened further after China and Thailand halted jet fuel exports and South Korea capped shipments at previous levels.

Walsh said a resumption of crude flows could encourage exporters such as China and South Korea to restart shipments of refined products, easing pressure on the market over time.

However, he noted that higher refinery margins, known as crack spreads, would be needed to incentivize increased jet fuel production.

“There is capacity available once we get the crude oil flowing, but it’ll take a little bit of time,” Walsh said.