Commercial oil stocks are depleting "very fast" as Gulf supplies remain disrupted due to the U.S.-Israeli-Iran war, even with the release of strategic reserves by governments worldwide, the head of the International Energy Agency (IEA) warned Monday.

Fears of shortages are rising with the summer travel season approaching in the northern hemisphere. Airlines have warned of jet fuel scarcity in weeks if supply disruptions persist.

"The commercial inventories are declining... I think it's depleting very fast now," Fatih Birol told journalists as he arrived for a meeting of G-7 finance ministers in Paris.

"We have still several weeks, but we should be aware of the fact that they're declining rapidly," he said, warning that "these are not endless."

Iran has effectively halted tanker traffic through the Strait of Hormuz in retaliation for U.S. and Israeli strikes launched in late February, choking off oil and gas traffic and sending prices soaring.

The IEA said this month that countries are tapping into oil inventories and their strategic reserves at a "record pace" as talks to end the war founder.

U.S. President Donald Trump threatened Sunday that "the clock is ticking" and "there won't be anything left" of Iran if no peace deal is reached amid a fragile truce.

The IEA has coordinated the release of 426 million barrels from emergency stocks by its 32 member countries, and said this month that around 164 million barrels have already been drawn.