Tim Armitage, an investment strategist at Quilter Cheviot, said the numbers mentioned by Trump were "relatively small".

He said the first tranche equated to approximately 2.25 million barrels, and daily US consumption was around 3.8 million barrels, "so it won't make a material difference to pump prices in the US".

"Granted, there are then two more releases to come, but it does appear to be a slightly desperate move by President Trump to try to lower inflation ahead of the midterms."

The BBC has asked the White House what Russia will get from the US in return for the commitment.

The agreement with Russia also opens Trump up to criticism from European allies and pro-Ukraine politicians in the US that the American president is now helping to fund Moscow's war machine.

The EU's foreign affairs chief Kaja Kallas said suspending sanctions "provides Moscow with more revenues to wage war", adding: "This is not the time to ease pressure on Russia, and Europe won't."

She said European foreign ministers intended to approve the biggest set of sanctions on Russia since the start of its full-scale invasion on Monday.

Meanwhile, a UK government spokesperson said its position "could not be clearer" and that it would continue working with international partners to support Ukraine and bring about sustained peace.

"We will also maintain pressure on Russia through the toughest sanctions regime ever imposed by the UK, increasing the cost of Putin's aggression and supporting efforts to secure a just and lasting peace."

Friday's announcement is the latest effort from Trump to lower fuel prices in the US ahead of the midterm elections, after months spent grappling with the political consequences of the Iran war.

That conflict, which began in February, has sent the cost of petrol and in particular diesel skyrocketing, which has soured his standing with the American public who have been stung by the higher pump prices and knock-on effects that led to across-the-board inflation.

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