Global energy markets are more than a year away from returning to normal and remain highly vulnerable to “overlapping crises” in the Middle East, the head of the International Energy Agency has warned.

His comments come as oil prices have been marching upwards in recent weeks. Brent crude, the global oil benchmark, is trading above $111 a barrel. If it stays there, it could settle at its highest level since May.

“I don’t see any credible pathway that 2027 will be a year of normalisation,” IEA executive director Fatih Birol told an industry gathering in London Tuesday. The Strait of Hormuz has been closed once, “it can be closed again,” he said.

The waterway, which transported a fifth of the world’s oil and natural gas supply before the war, has become heavily contested with attacks on ships ramping up in recent weeks.

“I’m very worried that there will be some overlapping crises in the Middle East … and it may further escalate the situation, which will have serious implications for energy markets,” Birol told the Financial Times Energy Transition Summit.

Higher oil prices reflect concerns that the US-Iran conflict could escalate. Iran has signalled that it is preparing for another round of war, issuing public threats against Washington in an apparent bid to deter President Donald Trump from reigniting the current stalemated conflict.

At the same time, Saudi Arabia has faced deadly attacks from Iran-backed Houthi militants in recent weeks, disrupting oil shipments and prompting the kingdom to call off its flagship investor conference, planned for later this month, just a week before it was due to take place.

Oil is flowing out of the Middle East despite the volatile situation. The latest seven-day moving average of oil flows from the region – including via Hormuz, the Red Sea and the Gulf of Oman – is above its pre-war average at just over 24 million barrels a day, Kpler data showed Tuesday.

While tanker crossings through the strait are still well below pre-war levels, a restoration in Saudi Arabia’s pipeline exports has helped restore flows and keep a lid on oil prices.

But Birol cautioned that assessing the depth of the current energy crisis by looking only at crude prices – which have not gone as high as $200 a barrel, as some analysts had predicted at the start of the war – was “myopic.”“We don’t use crude oil, we use products,” he noted, pointing to the fact that diesel prices have doubled from levels before the war, due largely to the Iran war but also in part to attacks on refineries in Russia.

“We are entering a season where diesel demand typically goes up” and many large refineries have planned maintenance work, he said. “We are on thin ice and I am very worried about this.”He said that IEA member countries, which total 32, “will not hesitate to look into the option of releasing further stocks” of oil reserves should they be needed.

IEA members agreed a historic release of emergency reserves in March, with 80% of those 400 million barrels already issued to the market and 20% still to be released. Member countries still have about 1.6 billion barrels “in pocket,” noted Birol. “We are keeping it for the rainy days.”