Europe could face major disruptions to air travel within weeks if energy supplies remain constrained, with as little as six weeks of jet fuel left, according to the head of the International Energy Agency, who warned that the ongoing Iran conflict is creating an unprecedented global energy emergency, the AP reports.

Fatih Birol, the IEA’s executive director, described the situation as deeply alarming in an interview Thursday, pointing to the severe impact of restricted oil and gas flows through the Strait of Hormuz. He characterized the situation as “the largest energy crisis we have ever faced,” with far-reaching consequences.

“In the past there was a group called ‘Dire Straits.’ It’s a dire strait now, and it is going to have major implications for the global economy. And the longer it goes, the worse it will be for the economic growth and inflation around the world,” he told The Associated Press.

Birol said the fallout will be felt through rising energy costs across the board. “higher petrol (gasoline) prices, higher gas prices, high electricity prices,” he said, speaking from his office in Paris overlooking the Eiffel Tower.

He warned that while all nations will be affected, the burden will fall most heavily on less-developed economies. “the countries who will suffer the most will not be those whose voice are heard a lot. It will be mainly the developing countries. Poorer countries in Asia, in Africa and in Latin America,” said the Turkish economist who has led the IEA since 2015.

Without a resolution that reopens the Strait of Hormuz, Birol said the consequences will extend to every nation. “Everybody is going to suffer,” he added.

He stressed that no country will be insulated from the impact. “Some countries may be richer than the others. Some countries may have more energy than the others, but no country, no country is immune to this crisis,” he said.

With nearly one-fifth of the world’s oil passing through the strait under normal conditions, Birol warned that prolonged disruption could deepen the crisis. “In Europe, we have maybe six weeks or so (of) jet fuel left,” he said. “If we are not able to open the Strait of Hormuz … I can tell you soon we will hear the news that some of the flights from city A to city B might be canceled as a result of lack of jet fuel.”

Airlines have not yet reported immediate shortages. Dutch carrier KLM and UK-based easyJet both said Thursday they are not currently facing fuel supply problems, though they declined to elaborate on the IEA’s warning. However, both companies have already been dealing with increased fuel costs.

KLM has announced it will reduce 160 flights to and from Amsterdam’s Schiphol Airport next month—about one percent of its European schedule—citing “rising kerosene costs” and noting that some routes are “no longer financially viable to operate.”

Passengers are already beginning to feel the impact, as airlines raise fares and add fees even before widespread cancellations have begun.

Birol said government leaders have warned him that the situation could deteriorate rapidly if the strait remains closed. “Many government leaders tell me that if Hormuz is not open until (the) end of May, many countries — starting from the weaker economies — are going to face huge challenges, and this will go from the high inflation numbers to coming close to slow growth or even to recession in some cases.”

He also criticized Iran’s practice of charging certain vessels to pass through the waterway, warning that such a system could spread to other key global shipping routes. “If we change it once, it may be difficult to get it back,” he said. “It will be difficult to have a toll system here, applied here, but not there.”

“I would like to see that the oil flows unconditionally from the point A to point B,” he said.

Birol noted that more than 110 oil tankers and over 15 liquefied natural gas carriers are currently stuck in the Persian Gulf and could help ease shortages if allowed to pass, but cautioned that even this would not fully resolve the crisis. “But it is not enough.”

He added that damage to regional energy infrastructure will slow any recovery even if fighting ends. “Over 80 key assets in the region have been damaged. And out of these 80, more than one third are severely or very severely damaged,” he said.

“It will be extremely optimistic to believe that it will very quick,” Birol said. “It will take gradually, gradually, up to two years to come back where we were before the war.”

Birol also expressed frustration that a relatively small force has been able to disrupt global markets. He said it is difficult to comprehend how “a couple of hundred men with guns” could hold the world economy at risk, noting that the IEA has long warned about the vulnerability of the Strait of Hormuz.

Looking ahead, he suggested the crisis may accelerate investment in alternative energy sources, including nuclear power, and could permanently alter global energy dynamics. “will reshape the global energy map for the next years to come,” he said.

Reflecting on the broader implications, Birol pointed to the deep connection between energy and global conflict. “Energy and geopolitics have been always interwoven,” he said. “But I have never, ever seen … such a dark and long shadow of geopolitics.”

He concluded on a somber note, saying: “Unfortunately, energy is at the heart of many conflicts which, again, makes me, as an energy person, rather sad, to be honest.”