President Donald Trump holds a joint news conference with President Klaus Iohannis of Romania, in the Rose Garden at the White House in Washin…

President Donald Trump holds a joint news conference with President Klaus Iohannis of Romania, in the Rose Garden at the White House in Washin…

Former FBI Director James Comey testifies before the Senate Intelligence Committee on Capitol Hill, in Washington, June 8, 2017. (Doug Mills/T…

Sen. Mark Warner (D-Va.), the ranking member, center, and Sen. Richard Burr (R-N.C.), right, chairman of the Senate Intelligence Committee, co…

Former FBI Director James Comey prepares to testify before the Senate Intelligence Committee on Capitol Hill, in Washington, June 8, 2017. The…

FILE - James Comey, the FBI director, testifies at a Senate hearing on Capitol Hill in Washington, May 3, 2017. The White House said on Monday…

FILE - James Comey, the FBI director, testifies at a Senate hearing on Capitol Hill in Washington, May 3, 2017. The White House said on Monday…

FILE -- Joe Lieberman, the former Democratic senator and vice-presidential nominee, departs the White House in Washington, May 17, 2017. Liebe…

Michael Flynn, President-elect Donald Trump's choice for national security adviser, at Trump Tower in New York, on Dec. 12, 2016. Before Trump…

FBI Director Robert Mueller III testifies during a hearing on Capitol Hill, in Washington, May 16, 2013. The Justice Department has appointed …