The Ukrainian president spoke to several allies on Saturday to discuss the latest developments, calling for "real decisions to protect lives in Ukraine" and to protect European security.

A Downing Street spokesperson said UK Prime Minister Andy Burnham had spoken to Zelensky and offered his "complete solidarity".

The pair had agreed Russia should acquiesce to "an immediate energy ceasefire" and end its attacks on shipping in the Black Sea, the spokesperson said, as "this would immediately release more energy and food supplies into the global market".

News of the US-Russia diesel deal was also met with criticism by EU's foreign affairs chief Kaja Kallas, who echoed Zelensky in saying that 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.

The deal with Russia 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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