U.S. President Joe Biden and Russian President Vladimir Putin will speak over phone on Saturday amid escalating tensions along the Ukrainian-Russian border. 

Kremlin spokesman Dmitry Peskov said on Friday that the phone conversation will take place on Saturday at the request of Washington. 

"Indeed, the U.S. side requested a conversation with President Putin, and the talks between the two presidents are planned to take place tomorrow in the evening," Peskov told reporters. "The request was preceded by a letter from the U.S. side." 

A White House official said on Friday that the call was first proposed by Russia. 

"They will be speaking Saturday morning. Russia proposed a call Monday. We counter-proposed Saturday, and they accepted," the official said.

It will be the third set of talks between Biden and Putin over Ukraine in just over two months. The two leaders held a video conference on December 7 and a phone conversation at the end of last year. 

France's President Emmanuel Macron will also speak with Putin on Saturday. 

White House National Security Advisor Jake Sullivan warned on Friday that a Russian attack on Ukraine "could occur any day now." The United States said it is sending 3,000 more troops to Poland to reassure NATO allies. 

Top U.S. General Mark Milley spoke by telephone on Friday with his Russian counterpart General Valery Gerasimov, the Pentagon said. 

Meanwhile, the European Union has told non-essential staff from its diplomatic mission in Ukraine that they should leave the country, but has not issued an evacuation order, a spokesman said Friday.

Russia has consistently denied that it is planning to invade Ukraine. 

Russian Defense Minister Sergei Shoigu urged Western countries to reduce tensions in Europe and stop supplying weapons to Ukraine during a meeting with UK Defense Secretary Ben Wallace, TASS reported on Friday. 

Moscow has asked Washington to prevent further eastward expansion of NATO and deny former Soviet republics accession to the alliance. Russia has also demanded that the U.S. and NATO not deploy offensive weapons in its neighboring countries. 

(With input from agencies)