Sally Yates, the former acting USA attorney general, told a Senate committee she warned White House officials about Flynn's call 18 days before any action was taken. The Lt. General's (Ret) resignation came amidst reports that he told Russian Ambassador Sergey Kislyak that the USA would lift sanctions on Russia when Trump won the White House.
CNN also reported White House lawyers started preparing for possibility of Trump's impeachment.
Flynn's time at the White House lasted just 24 days.
The network cited unnamed sources who said that the Russians saw Flynn as an ally. Regardless, it was extraordinarily ill-advised for the President of the United States to contact a White House employee he fired, especially to offer support, after asking the FBI Director to drop the Bureau's investigation.
Since he resigned, Flynn - who denies wrongdoing - has retained a lawyer and offered to testify in exchange for immunity from prosecution. [Image by Russian Foreign Ministry Photo/AP Images] As the Trump administration becomes further mired in the deepening alleged Russia connection scandal, more and more people are demanding answers to questions surrounding the extent of involvement Trump's campaign had with the Russians and how much involvement still exists. Flynn is one of several Trump associates under federal investigation by special counsel Mark Mueller for collusion with Russian Federation and obstruction of justice.
But according to friends of the retired Army general, Trump insisted he take the position, and Flynn, "reluctant but honored" by the offer, accepted. Mueller will have sweeping powers, including the right to bring federal charges.
Michael Flynn speaks at the 2016 Republican National Convention.
But Flynn apparently gave indications that he is not going to turn on Trump. "We still have to know more ... about how Russian Federation corrupted our democracy", he said. "I was kind of stunned", one person said.
On Wednesday afternoon, Deputy Attorney General Rod Rosenstein announced his appointment of Robert Mueller as special counsel for the Russian Federation investigation with little notice given to the White House.
In his view, this effort began immediately after the election, when President Barack Obama, who had fired Mr. Flynn as the head of the Defense Intelligence Agency, told Mr. Trump that he would have profound concerns about Mr. Flynn's becoming a top national security aide. However, officials can request that they be revealed for intelligence purposes.
Trump opens first presidential trip overseas in Saudi Arabia
Trump made Saudi Arabia his initial stop Saturday on his first official trip overseas, before visiting Israel and the Vatican. Trump and Salman spoke through an interpreter inside the airport terminal after the president stepped off Air Force One.
What is a special counsel?
The deputy attorney general's hotly-anticipated meeting with senators came less than 24 hours after he appointed Mueller. Associates of Mr Comey has also claimed that the president asked him to pledge his loyalty shortly after taking office.