Washington: US President Joe Biden has been urged by a group of former US diplomats and national security officials to publish a list of measures that the US would apply on Russia immediately if tensions over Ukraine intensified.

"We believe the US should take prompt actions to influence the Kremlin's cost-benefit calculations, in close cooperation with NATO partners and Ukraine, before the Russian leadership opts for further military escalation. This means that the costs of a new Russian military assault on Ukraine would be increased "In a statement released on the website of NATO's think-tank, the Atlantic Council, on December 30, former officials said.

Former officials also advised the US government and NATO partners to seek de-escalation before engaging in any serious talks with the Kremlin, which should include all parties whose security or interests are at risk. Former US ambassadors to Russia Michael McFaul and Alexander Vershbow, former State Department special envoy for Ukraine Kurt Volker, and eminent political scientist Francis Fukuyama, author of The End of History, were among those who signed the statement.

Biden spoke by phone with Russian President Vladimir Putin late Thursday, during which they addressed European security and the increase of tensions over Ukraine.

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