US defence secretary Lloyd Austin has arrived in Kyiv on an unannounced visit, hours after a Russian drone attack on the Ukrainian capital and as Ukraine President Volodymyr Zelensky pushes Western partners to keep providing military support for the war.

Mr Austin said on the X platform that his fourth visit shows “that the United States, alongside the international community, continues to stand by Ukraine”.

Ukraine is having difficulty holding back a ferocious Russian campaign along the eastern front that is gradually compelling Kyiv’s forces to give up a series of towns, villages and hamlets.

Mr Zelensky is urging Western allies to support his so-called “victory plan” to end the almost three-year war, which is Europe’s biggest conflict since the Second World War and has cost tens of thousands of lives on both sides, including many civilians.

His strategy includes a formal invitation for Ukraine to join Nato and permission to use Western long-range missiles to strike military targets in Russia — steps Kyiv’s allies have previously baulked at supporting.

Russian strikes continue in Kharkiv (Ukrainian Emergency Service via AP)

The Western response has been lukewarm, and Mr Austin was expected to discuss the plan with Ukrainian officials in Kyiv.

Mr Zelensky said his plan had won the backing of France, Lithuania, Nordic countries and “many other allies” in the European Union which he did not name.

The key country, however, is the United States, which is Ukraine’s biggest military supplier.

Mr Zelensky said he had received “very positive signals from the United States”, but he stopped short of saying he had secured Washington’s endorsement for the plan.

Russia fired three missiles and 116 Shahed drones at Ukraine overnight from Sunday to Monday, Ukraine’s air force said.

Machine gun fire and the noise of drones’ engines was heard in Kyiv’s centre throughout the night.

Authorities reported minor damages to civilian infrastructure caused by falling drone debris in the three districts of the city.