In its latest market report, the IEA said crude oil production was currently down by at least 8.0 million bpd, with an additional 2.0 million related to petroleum products including condensates shut off.

The conflict, which was triggered on February 28 by American-Israeli attacks on Iran, is hampering the global economy's supply of oil and weakening production capacity.

The war has seen Iran tighten its chokehold on the Strait of Hormuz, a vital transit point for oil trade, reducing supplies to a trickle with the strait, through which a fifth of global crude passes, effectively all but shut down.

IEA said current flows through the strait were moving at less than 10 percent of pre-crisis levels, which in 2025 were around 15 million barrels per day -- with "no signs of a de-escalation in hostilities or a clear timeline for a recovery in flows through the Strait."

It stressed that a resumption of lows would be key in minimising the impact from the war on global markets.

Against that stark backdrop, major European stock markets were off more than half of one percent in early morning trading. In Asia, Japan's Nikkei had shed one percent at the close while Hong Kong closed off 0.7 percent.

A threat from Tehran to bring down the global economy overshadowed an impending record release of strategic crude by the IEA which Wednesday said its 32 members had agreed to unlock 400 million barrels of oil from reserves -- their largest release ever.

"The co-ordinated emergency stock release provides a significant and welcome buffer, but in the absence of a swift resolution to the conflict, it remains a stop-gap measure," the IEA warned.