IEA executive director Fatih Birol painted a sobering picture of the global repercussions of what he called "the largest energy crisis we have ever faced", stemming from the pinch-off of oil, gas and other vital supplies through the Strait of Hormuz.
"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 Associated Press.
The impact would be "higher petrol prices, higher gas prices, high electricity prices", Birol told AP.
Economic pain would be felt unevenly, with some countries "hit worse than the others", he said, naming Japan, Korea, India, China, Pakistan and Bangladesh as being on the front line of the energy crisis.
"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," he said.
"Then it will come to Europe and the Americas," he said, speaking from his Paris office looking out over the Eiffel Tower.
If the Strait of Hormuz was not reopened, he said that for Europe, "I can tell you soon we will hear the news that some of the flights from city A to city B might be cancelled as a result of lack of jet fuel".
Birol spoke out against the so-called "toll booth" system that Iran has applied to some ships, letting them travel through the strait for a fee.
He said that allowing that to become more permanent would run the risk of setting a precedent that could then be applied to other waterways, including the vital Malacca Strait in Asia.
"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.
