Berlin, on the other hand, was reluctant to release any barrels, according to the people. "Germany and others don't want to be used; they wish to release stocks only for real security of supply reasons," one of them told POLITICO, speaking on condition of anonymity to speak candidly, as with others in this piece. Germany and France have the largest reserves of oil and petroleum products in Europe, according to official EU statistics.

"France is keen to participate and meet the request ... it's clear the EU will do something, to the extent they can agree on something," said the second person. They added that it was unclear whether the release would be jointly coordinated by the EU or done on a bilateral basis, given the "messy" approach by the U.S., which has sent different requests to different countries. "It's a typical US request — they don't go through the official normal channels."

A spokesperson for French Economy Minister Roland Lescure dismissed the proposal as "rumors" and declined to comment further. In a statement, the Elysée palace said Emmanuel Macron will convene a meeting of G7 leaders "as soon as possible to coordinate the measures needed to help ease the pressure on prices and ensure the supply of crude oil and refined products among G7 countries and globally."

Macron had a phone call with U.S. President Donald Trump on Thursday night to "discuss the global energy situation" and "ensure the global availability of refined products," the Elysée said.

U.K. officials are expecting a G7 meeting to be convened as soon as Friday, but immediate outcomes are unlikely, according to a person familiar with the matter, granted anonymity to discuss sensitive fuel supply issues. Any European release of reserves would be IEA-led, the person said.

The U.S. is increasingly frustrated at EU countries that have failed to deliver on commitments to contribute to the 400 million barrel release coordinated earlier this year by the International Energy Agency following the outbreak of the war in Iran and the closure of the Strait of Hormuz. In the high-level Energy Union Taskforce meeting Friday, some EU countries also rounded on France and Germany for their failure to release substantial oil reserves into the market, according to one of the people.

POLITICO reported Thursday that leading EU countries and the U.K. wanted to respond to the U.S. pressure with an "assertive" voice while seeking to de-escalate.

Nicolas Camut and Charlie Cooper contributed reporting.