WASHINGTON, Dec 1 (AFP) - The presidents of the United States and France vowed to hold Russia to account for its actions in Ukraine and the European Union reached tentative agreement on Thursday (Dec 1) on an oil price cap aimed at starving Moscow of resources.

Western powers are trying to rally support for Ukraine, which is reeling from massive, near weekly missile and drone attacks targeting power supply, water and heat in its cities just as winter has set in nine months into Russia's invasion.

Russia meanwhile accused the United States and NATO of playing a direct and dangerous role in the war and said Washington had turned Kyiv into an existential threat for Moscow which it could not ignore.

Speaking after an Oval Office meeting with French President Emmanuel Macron, US President Joe Biden said that "France and the United States are facing down Vladimir Putin's grasping ambition for conquest" and "defending the democratic values and universal human rights".

Biden told reporters he was "prepared to speak with Mr Putin, if in fact there is an interest in him deciding he's looking for a way to end the war", but added that Putin "hasn't done that yet".

There are no political talks under way to end the war, which Russia launched as a "special military operation" claiming its aim was to disarm its neighbour and root out leaders it characterises as dangerous nationalists.

Kyiv and the West call it an imperialist land grab, which has killed tens of thousands of Ukrainian civilians and soldiers on both sides. Ukraine's armed forces have lost somewhere between 10,000 and 13,000 soldiers so far in the war against Russia, presidential adviser Mykhailo Podolyak told a Ukrainian television network on Thursday.

"We will never urge the Ukrainians to make a compromise which will not be acceptable for them, because they are so brave," Macron said.

In a bid to cut resources available for Moscow's war effort, the European Union tentatively agreed on Thursday on a US$60 a barrel price cap on Russian seaborne oil, according to diplomats. The measure would need to be approved by all EU governments in a written procedure by Friday.