PARIS — A group of the world’s top economies has agreed to release 400 million barrels of oil, in a bid to counter soaring prices and the risk of a supply shock from the war in Iran.

The agreement was reached following a meeting on Tuesday of the 32 members of the International Energy Agency, which include the U.S., Japan, Germany, the U.K. and France.

It will represent the largest release of reserves in the body’s history, and is more than twice the 182 million barrels of oil IEA countries released following Russia’s invasion of Ukraine in 2022.

The historic decision reflects growing fears that the U.S. and Israeli attacks on the oil-rich region are escalating into a deep global energy crisis.

“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,” said IEA Executive Director Fatih Birol.

The oil will be made available “over a timeframe that is appropriate to the national circumstances of each Member country,” an IEA statement released on Wednesday read.

Earlier this week, G7 countries already signaled support for the measure, which is aimed at keeping oil prices under control by increasing supply. 

Right after the IEA announcement, French President Emmanuel Macron chaired a virtual meeting of G7 leaders to discuss the economic consequences of the war in Iran. 

“G7 represents 70 percent of this announcement,” Macron said as he opened the meeting. The French president also urged G7 countries to look into “everything we can do in order to increase our global production.”   

The release “sends a clear signal to lower global prices,” Macron said after the G7 meeting. 

The Paris-based IEA, a key venue for wealthy countries to coordinate oil and gas supplies set up after the 1973 oil embargo, first proposed the measure late Tuesday during an extraordinary all-members meeting that followed a gathering of the G7 energy ministers.  

Oil prices soared to over $100 a barrel over last week as Iran struck energy infrastructure across the Persian Gulf in response to U.S.-Israeli airstrikes across Iran, which closed the Strait of Hormuz, the narrow waterway through which a fifth of global oil trade passes. The oil price retreated to around $90 a barrel after G7 countries signalled this week that they were in principle supporting the oil release.  

Countries had initially hoped the conflict would be shortlived and have a limited impact on energy supply. But fears of a prolonged crisis have grown as the Strait of Hormuz remained closed and bombardments from both sides forced numerous oil and gas plants in the region to stop production.

The U.S., Japan and South Korea were the most enthusiastic supporters of releasing the stockpiles, according to two EU officials familiar with the matter. European countries, which import a relatively small amount of oil from the Gulf, were more reluctant at first, but were ultimately convinced, according to another EU energy official. 

The EU’s energy commissioner Dan Jørgensen welcomed the decision in a social media post. “In times of hardship, unity and global cooperation are essential,” he wrote, announcing a meeting of the bloc’s oil coordination group for Thursday. 

EU countries — some of which are not IEA members — will meet to discuss how to coordinate the release at a meeting that will include national ministerial and EU officials on Thursday, followed by a gathering on energy ministers on Monday, according to an EU official familiar with the matter.  

One EU official and one national official suggested it might prove a challenge to ensure that oil stocks are refilled promptly to meet EU reserve requirements before the winter, which could be difficult if the supply disruption in the Strait of Hormuz endures.  

The IEA said it will provide more details on implementation in due course. Some member countries have already indicated how much they are willing to contribute, including the U.K., which said it would provide 1.3 million barrels out of a total 76.6 million barrels in total reserves.  

“With this action, the UK is playing our part in working with our international allies to address the disruption in oil markets,” U.K. Energy Secretary Ed Miliband said in a statement. “The UK has strong and diverse energy supplies, and the price cap plays an important role in protecting energy bills until July.

This story has been updated.