"We must not allow Russia to blur reality or mislead the world. Moscow must be forced into diplomacy," Zelensky said in a video address to defence ministers meeting in Brussels.

The call for action comes as Kyiv's main backer the United States has stepped back from its support for Ukraine under President Donald Trump and pushed for a quick end to the fighting unleashed by Russian leader Vladimir Putin.

In a sign of Washington's disengagement, US Defense Secretary Pete Hegseth missed the gathering in Brussels, despite being due to fly in for a NATO meeting on Thursday.

In his address, Zelensky urged allies to step up deliveries of air defences to ward off Russia's missile and drone attacks, and to bolster Ukraine's own defence industry.

"The stronger our air defence is, the less value Putin sees in attacking our cities and villages. So please, let's continue strengthening our air shield," the Ukrainian leader said.

Britain's Defence Secretary John Healey said Russia was "routinely firing over 300 drones a day into Ukraine".

"This is a significant shift, and this is a rate of fire that could be sustained throughout 2025," he said.

"Three and a half years into this war, President Putin continues to prove he's not for peace."

Healey's German counterpart Boris Pistorius insisted Russian forces "are making hardly any progress" on the front line and suffering devastating losses.

He said Russia would eventually fail in its push to control Ukraine as Kyiv's backers were providing it "with everything it needs and for as long as it needs".

"We will continue to expand this support, and we will maintain it for the long term," he said.

Despite the soaring rhetoric, there were few public pledges of concrete new weapon deliveries for Kyiv at the meeting.

Britain said it would step up supplies of drones to Kyiv "tenfold" and the Netherlands announced naval support worth 400 million euros ($450 million).