WASHINGTON, February 15. /TASS/. Michael Flynn has resigned from the position of the U.S. president’s national security adviser due to the loss of the president’s trust, White House spokesman Sean Spicer has told reporters.

"At some point that trust eroded to a point where the president did not feel comfortable with him serving in that position and asked for and received his resignation," Spicer said at a media briefing late Tuesday.

He said that while dealing with many international issues, the president "needs to rely - on an actual security advisor to give them sage advice." Such relationship is impossible with the loss of trust, so Donald Trump asked his adviser to submit his resignation, the spokesman added.

Spicer said that although the discussion was not authorized by the president, it was concluded that Flynn did not violate any law or protocol. It was only an issue of trust that led to the resignation, he added.

Claims published by the Washington Post earlier suggested Flynn had discussed the US anti-Russian sanctions with the Russian Ambassador in Washington, Sergei Kislyak. The telephone consultations presumably took place a month prior to the inauguration of President Donald Trump.

The Washington Post said some officials in the administration thought the talks between the would-be national security adviser and the Russian ambassador might have sent an irrational and theoretically incorrect signal to Moscow and the sanctions, which the Obama administration had introduced in the wake of the 2014 reunification of Crimea and Sevastopol with Russia, could be eased.

In his resignation letter provided by the White House, Flynn acknowledged that he had inadvertently provided US Vice President Mike Pence and others with "incomplete information" on his contacts with the Russian ambassador.

"Unfortunately, because of the fast pace of events, I inadvertently briefed the Vice President Elect and others with incomplete information regarding my phone calls with the Russian Ambassador. I have sincerely apologized to the President and the Vice President, and they have accepted my apology," he said in the letter.

The Kremlin refuted the Washington Post’s allegations, with the presidential press secretary Dmitry Peskov saying that, to the best of his knowledge, the consultations between Flynn and Kislyak did take place but the right place to get a confirmation was the Russian Foreign Ministry. "As for the rest, the information is incorrect," he said.

The White House said in a statement Gen Joseph Keith Kellogg was named Trump’s acting national security adviser.