Xinhua file photos of Russian President Vladimir Putin (L) and U.S. President Joe Biden

 
U.S. President Joe Biden on Tuesday called on Russia to de-escalate its tensions with Ukraine in his phone call with Russian President Vladimir Putin, the White House said.

The president voiced concerns over the sudden Russian military build-up in Crimea and on Ukraine's borders, and called on Russia to de-escalate tensions, the White House said in a statement.

Biden also emphasized the U.S. unwavering commitment to Ukraine's sovereignty and territorial integrity to his Russian counterpart.

He also made clear that the United States will "act firmly in defense of its national interests in response to Russia's actions, such as cyber intrusions and election interference."

The statement said that the two leaders "discussed a number of regional and global issues, including the intent of the United States and Russia to pursue a strategic stability dialogue on a range of arms control and emerging security issues, building on the extension of the New START Treaty."

Biden also proposed holding a summit with Putin in a third country in the coming month to discuss the full range of issues between Washington and Moscow.

The phone call came amid escalating tensions in eastern Ukraine and Russian troops movements along its borders with Ukraine.

The White House said last week that Russia had deployed more troops along the border with Ukraine than any time since 2014 when the conflict in eastern Ukraine broke out. The ongoing conflict has killed some 14,000 people and left as many as 40,000 wounded.

Russian Deputy Foreign Minister Sergei Ryabkov on Tuesday urged that NATO countries shift their focus to curbing Kiev's belligerent sentiment and ensure Ukraine's compliance with the Minsk agreements on a settlement of the Donbas conflict.