Ukraine’s counter

Speaking at a White House press conference with Rishi Sunak, Joe Biden, the US president, said he was “very optimistic” about the “evolving” situation.

Mr Sunak said it was “totally reasonable” for the American people to ask allies to “do their part”, adding that the UK was “proud” to be the biggest contributor behind the US to the military effort.

He said: “I think it is important other nations step up and do their part. President Putin will be thinking that the alliance will tire, will get fatigued, and that is not the case.”

Russia published a video of a long column of Ukrainian vehicles under heavy attack, as Vladimir Putin, the Russian president, was personally briefed on the “heavy losses” inflicted on Ukraine.

It came as Russia shelled the Ukrainian city of Kherson, targeting civilians evacuating the floodwaters after a major dam sent a torrent of water downstream.

Volodymyr Zelensky, the Ukrainian president, visited the city moments before the barrage rained down.

On Thursday Jens Stoltenberg, head of Nato, urged members of the alliance to speed up humanitarian assistance to Ukraine after the destruction of the dam.

The Ukrainian offensive appeared to be focussed around the Ukrainian-held front-line town of Orikhiv, with analysts suggesting Kyiv was intending to push down towards the coast and cut off Russia’s access to Crimea.

But Russia claimed to have largely repelled the attack. Ukrainian and Western officials have long warned that the counter-offensive would be difficult, even with fresh supplies of modern Nato-standard equipment like main battle tanks.

The Russians have prepared multi-layered defensive lines several miles deep in Zaporizhzhia, including minefields, trenches, and tank traps.