The European Union has proposed its toughest sanctions yet against Russia, including a phased oil embargo, as Moscow pressed an offensive in eastern Ukraine and close ally Belarus announced large-scale army drills.

The European Union has vowed to increase pressure on Russia "until Ukraine is liberated" as it adopted a tenth package of sanctions on Russia, a day after the first anniversary of the invasion of Ukraine.

Ukraine has attacked Moscow with at least 34 drones, the biggest drone strike on the Russian capital since the start of the war in 2022.

Russian bombs have rained down on Ukrainian cities, Ukrainian official say, despite talk of compromise from both Moscow and Kyiv in peace negotiations after three weeks of war.

Western allies have announced sweeping new sanctions against Moscow as a defiant President Volodymyr Zelenskiy said Ukrainian forces were repelling Russian troops advancing on Kyiv.

Russian President Vladimir Putin has shown no regrets for his war in Ukraine, insisting the "special military operation" was still achieving its goals and the West's dominance over world affairs is coming to an end.

Ukraine says its forces had recaptured villages from Russian troops north and northeast of the city of Kharkiv, pressing a counteroffensive that could signal a shift in the war's momentum and jeopardise Russia's main advance.

A veteran envoy of President Vladimir Putin has resigned over the Ukraine war and left Russia with no intention to return, two sources say, as US President Joe Biden prepares to visit Europe for talks.