"The oil market challenges we are facing are unprecedented in scale, therefore I am very glad that IEA member countries have responded with an emergency collective action of unprecedented size," IEA executive director Fatih Birol said in a statement.

"Oil markets are global so the response to major disruptions needs to be global too."

The 32 countries at an emergency meeting "unanimously agreed today to make 400 million barrels of oil from their emergency reserves available to the market to address disruptions in oil markets stemming from the war in the Middle East", the statement said.

"The emergency stocks will be made available to the market over a timeframe that is appropriate to the national circumstances of each Member country and will be supplemented by additional emergency measures by some countries."

The US-Israeli war with Iran has effectively closed off the Strait of Hormuz, a crucial shipping route for oil and gas.

The IEA release far exceeds the 182 million barrels of oil that its member countries released in 2022 when Russian leader Vladimir Putin invaded Ukraine.

The 32 members of the IEA hold over 1.2 billion barrels of public emergency oil stocks, with a further 600 million barrels of industry stocks held under government mandates.