"We have been reviewing and evaluating this issue with respect to General Flynn on a general basis for a few weeks trying to ascertain the truth," White House Press Secretary Sean Spicer told reporters.
The White House admitted that Trump was told three weeks ago that Flynn may have misled colleagues about his Kremlin contacts ahead of the inauguration on January 20.
Flynn, 58, resigned yesterday after he apologised to Trump and Vice President Mike Pence for not providing them all the information about his call with the Russian Ambassador to the US Sergei Kislyak before Trump's inauguration.
Spicer said Trump was also very concerned in light of the sensitive subjects dealt with by the national security advisors with respect to China, North Korea and the Middle East, that he must have complete and unwavering trust for the person in that position.
More From This Section
Spicer said immediately after the Department of Justice notified the White House counsel of the situation, the counsel briefed the President and a small group of his senior advisors.
"The White House counsel reviewed and determined that there is not an illegal issue, but rather a trust issue. During this process, it's important to note the President did not have his attorney general, Jeff Sessions, who he trusts immensely, approved by the Senate," he said.
It is not ordinary for an incoming national security advisor to speak with his counterparts about the issues of concern to them. In fact, he spoke with over 30 of his counterparts throughout the transition," Spicer said.
"The issue here was that the President got to the point where General Flynn's relationship -- misleading the vice president and others or the possibility that he had forgotten critical details of this important conversation had created a critical mass and an unsustainable situation. That's why the President decided to ask for his resignation and he got it," he said.