Vladimir Putin has failed in his plan to capture Kyiv, with Moscow on Tuesday pledging to withdraw forces from the Ukrainian capital.
Russia claimed the withdrawal from Kyiv and the city of Chernihiv was to build trust in “constructive” peace negotiations.
Talks in Istanbul broke up on Tuesday after Ukraine offered to make itself permanently neutral if the UK, other Western powers and China provided military protection from future Russian aggression. But hours later, heavy shelling resumed in Kyiv.
Vladimir Medinsky, Russia’s chief negotiator, claimed Moscow did not want to “put Kyiv at military risk” because people whose decisions could bring peace, such as Volodymyr Zelensky, the Ukrainian president, were there.
But he said “de-escalation does not mean a ceasefire” and warned that there was still “a long way to go” before a deal could be signed.
Mr Zelensky on Tuesday night urged the world not to trust any Russian promises as fresh explosions rocked the capital.
“Of course, we see all the risks. Of course, we don’t have a reason to trust the words of representatives of a country that wages war against us,” he said. “Ukrainians are not naive.”
Boris Johnson said Putin could still seek to “twist the knife” despite Russia’s faltering invasion as the Cabinet decided to step up military aid to Ukraine.
After a call with the leaders of the UK, France, Germany and Italy, Joe Biden, the US president, said the West would “keep strong the sanctions” while following Moscow’s next moves.
Washington believes the withdrawal of troops from near Kyiv is merely a redeployment after the Russian invasion became bogged down in the north of the country.
Antony Blinken, the US secretary of state, said Russia’s “brutalisation” of Ukraine “continues as we speak”.
US officials warned that the world should be prepared for more major offensives elsewhere.
John Kirby, the Pentagon spokesman, said Russia had “failed in its objective of capturing Kyiv” but cautioned that the capital remained surrounded.
Putin’s close ally General Sergei Shoigu, the Russian defence minister, said the army’s priority was now the “liberation” of the Donbas in the east of the country, where two Russian-backed rebel regions broke away from Ukraine in 2014.
A Western official said the Russians were reinforcing the Donbas with battalion tactical groups to “envelop” Ukrainian forces in the area.
Denis Pushilin, a separatist leader, said the self-proclaimed, Russian-backed Donetsk People’s Republic would consider joining Russia once it controlled the whole Donetsk region.
Ukrainian forces have recently appeared to make significant territorial gains around Kyiv, Kharkiv and Kherson. They pushed Russian forces back from around Kyiv, including in the nearby town of Irpin, an important gateway to the capital.
“Our men crushed them and forced them to get back, so we will celebrate,” said Volkov Kostiantyn, a Kyiv resident. “But no alcohol until the war ends. Just coffee.”