The former national security adviser also won't turn over documents requested by the committee that is looking into Russian meddling in the presidential election.
The former national security adviser reportedly received $500,000 to lobby for Turkey which opposes the U.S. backing of Kurdish forces in Syria.
The ex-FBI director told a friend that a one-sided hug with the president left him feeling "disgusted."
A memo written by James Comey accused Trump of urging his former FBI director to end the federal investigation into Michael Flynn.
"Trump feels really, really, really, bad about firing him, and he genuinely thinks if the investigation is over Flynn can come back," a White House official told The Daily Beast.
Senate Intelligence Committee Chairman Richard Burr has expressed concern over whether Michael Flynn will comply with a subpoena issued last week.
The Obama administration's Justice Department notified the Trump transition team about Flynn's secret work as a lobbyist for the Turkish government weeks before inauguration.
The former acting U.S. attorney general's testimony will reveal "who knew what when" about Flynn's Russia contacts, says Senator Feinstein.
Michael Flynn, Trump's first national security adviser, had alarming contacts with Russians and Turk lobbyists, but still got a top-secret clearance.
Donald Trump's former national security adviser didn't receive permission as a former military officer for the 2015 trip, House Oversight chair says.
Abuse of power, misuse of government funds and, of course, sex scandals are as common in American politics as flag pins on lapels.
The former national security advisor had to amend his disclosure after leaving off payments for speaking engagements to Russian entities.
McMaster is joining the White House staff with views on Russia, counterterrorism, strengthening the military and other major security issues that diverge not only from those of the Trump loyalists, but also from those the president himself has expressed.
To reach the desk of the FBI director, the phone calls between Flynn and the Russian ambassador had to clear high counterintelligence hurdles.
He also named retired U.S. Army General Keith Kellogg, who had been serving as acting national security adviser, as chief of staff to the National Security Council.
The latest in a series of miscues has continued to plague the new administration as they push through the first 100 days.
Reports say President Trump has been reluctant to allow the eventual pick decision-making powers on staffing.