White House Press Secretary Sean Spicer said on Tuesday that President Trump had been aware for weeks that National Security Adviser Michael Flynn, who resigned Monday, misled Vice President Mike Pence and other officials about the nature of his call with the Russian ambassador to the United States. From the Washington Post:

Trump was briefed by White House Counsel Don McGahn that Flynn had discussed U.S. sanctions with the Russian ambassador “immediately” after McGahn was informed that Flynn had misled Pence, White House press secretary Sean Spicer said Tuesday.

“We’ve been reviewing and evaluating this issue with respect to Gen. Flynn on a daily basis for a few weeks, trying to ascertain the truth,” Spicer said.

Spicer said that Trump asked for Flynn’s resignation because “the level of trust between the president and Gen. Flynn had eroded to the point where he felt he had to make a change.”

On Friday, Trump told reporters on Air Force One he had been unaware of a Washington Post story revealing that Flynn had lied about his call:

Trump yesterday: "I don't know about that. I haven't seen it. What report is that?...I haven't seen that. I'll look into that." https://t.co/1aO9CKcc0g — Jake Tapper (@jaketapper) February 12, 2017

According to CNN, a handful of Republican senators on Tuesday joined Democratic calls for an investigation into Flynn’s call, including Sen. Roy Blunt, Sen. Lindsey Graham, and Senate Majority Whip John Cornyn. Senate Majority Leader Mitch McConnell told reporters Tuesday afternoon that a Senate Intelligence committee investigation into Flynn’s call is “highly likely.”