Russian President Vladimir Putin said Tuesday that he wants "immediate" talks with the United States and NATO over security guarantees, as tensions soar between Moscow and the West over Ukraine.

The U.S. and its NATO allies have for weeks accused Russia of planning an invasion of its neighbor and warned of a massive coordinated sanctions response should Putin launch such an attack. 

In a phone call with Finnish President Sauli Niinisto, whose country has traditionally served as a middle ground between Russia and the West, Putin said he wanted security talks to begin without delay. 

He told Niinisto that Moscow wants "to immediately launch negotiations with the United States and NATO in order to develop international legal guarantees for the security of our country," the Kremlin said in a statement. 

Russia's demands, it said, include stopping NATO from expanding eastwards and halting the deployment of weapons in neighboring states, including Ukraine.

Putin reiterated the same demands in a phone call with French President Emmanuel Macron later on Tuesday. 

Putin's comments came a day after Russia's Deputy Foreign Minister Sergei Ryabkov warned that Moscow could act militarily if the talks it demands do not materialize. 

"The lack of progress towards a political-diplomatic solution to this problem will lead to the fact that we will respond militarily," Ryabkov told the RIA Novosti state news agency.

Putin has denied planning an invasion, blaming the Western security alliance for the rise in tensions and demanding "legal guarantees" the alliance won't expand eastwards.

U.S. President Joe Biden last week warned Putin of "sanctions like he's never seen" should Russian troops massed near the Ukrainian border launch an attack. 

The EU and the G7 met in recent days to coordinate what they said would be an unprecedented economic sanctions regime if Russia attacks.  

(With input from agencies) 

(Cover: Russian President Vladimir Putin attends a session of the annual Valdai Discussion Club in Sochi, Russia, October 21, 2021. /Reuters)