The White House kept Vice President Pence in the dark for weeks about the warning it had gotten about national security adviser Michael Flynn from the Justice Department, Pence's press secretary, Marc Lotter, said Tuesday.

Pence did not find out until Feb. 9. Trump was first informed about the Justice Department's concerns regarding Flynn on Jan. 26, White House Press Secretary Sean Spicer said at Tuesday's daily press briefing.

Flynn's actions as President Donald Trump's short-lived national security adviser are under scrutiny after he resigned Monday night over phone calls he shared with Russia's ambassador to the United States in December — before Trump took office. Among the topics discussed included U.S. sanctions imposed by the Obama administration against Moscow for its alleged role in the 2016 presidential election.

The date the vice president knew is significant because it is when the administration became aware that the Washington Post was about to publish a heavily-sourced story that confirmed Flynn and the Russian ambassador discussed sanctions, despite public denials from Flynn and other incoming senior administration officials including Pence, then the vice president-elect.

Flynn's departure — so far the most high-profile of Trump's senior team — comes after the White House said he misled Pence and other senior administration officials about information he shared with Russian Ambassador Sergey Kislyak. Flynn had claimed that he had no substantial communication with Kislyak, which Pence later repeated to various news outlets.

More from NBC News:

Michael Flynn: A Timeline of His Rise and Fall and the Russia Call

Clinton Officials Denounce Alleged Trump Campaign Officials' Contacts With Russia

White House: 'Erosion of Trust' Led to Flynn Dismissal



In his resignation letter, Flynn, a retired Army lieutenant general, said "the fast pace of events" was to blame for his inadvertently briefing Pence and others with "incomplete information regarding my phone calls with the Russian Ambassador."

The Washington Post reported Monday that the Justice Department, led by then-Acting Attorney General Sally Yates, informed the White House last month that Flynn was not entirely forthcoming about the calls or their substance — opening him up to the possibility of blackmail by the Kremlin.

Yates also reportedly was concerned that Flynn could have violated the Logan Act of 1799, a rarely used law that bars unauthorized U.S. citizens from negotiating with foreign governments. However, a senior intelligence official told NBC News last week that there had been no finding that Flynn acted illegally.

