Michael Flynn, U.S. President-elect Donald Trump's pick for national security adviser, took a phone call last month from Russia's ambassador to the United States, Trump's spokesman said Friday.

The call between Flynn and Sergey Kislyak on Dec. 28 "centered around the logistics of setting up a call with the President of Russia and the President-elect after he was sworn in and they exchanged logistically information on how to initiate and schedule that call," Sean Spicer said.

The spokesman also said Flynn and Kislyak exchanged greetings during the Christmas holidays prior to the call.

The contacts between the Russian envoy and Trump's top aide came around the time U.S. President Barack Obama announced on Dec. 29 tough sanctions against Russian entities and individuals over alleged hacking during the 2016 U.S. presidential election.

Russian President Vladimir Putin decided not to retaliate against the sanctions -- a move that Trump praised as "very smart."

Trump, who has called for improving U.S.-Russia relations, on Wednesday conceded for the first time that Russia was behind cyberattacks during the presidential election.

Asked at the first press conference since his election win whether be believed Putin had directed the hacking to help him win the presidency, Trump said "If Putin likes Donald Trump, I consider that an asset, not a liability."

source: Xinhua