Michael Flynn Resigns As National Security Adviser

WASHINGTON — Michael T. Flynn, the national security adviser, resigned on Monday night after it was revealed that he had misled Vice President Mike Pence and other top White House officials about his conversations with the Russian ambassador to the United States.

Mr. Flynn, who served in the job for less than a month, said he had given “incomplete information” to about a telephone call he had with the ambassador in late December about American sanctions against Russia, weeks before Mr. Trump’s inauguration. Mr. Flynn previously had denied that he had any substantive conversations with Ambassador Sergey I. Kislyak, and Mr. Pence repeated that claim in television as recently as earlier this month.

But on Monday, a former administration official said the Justice Department last month warned the White House that Mr. Flynn had not been fully forthright about his conversations with the ambassador. As a result, the Justice Department feared that Mr. Flynn could be vulnerable to blackmail by Moscow.

In his resignation letter, which the White House emailed to reporters, Mr. Flynn said he had held numerous calls with foreign officials during the transition. “Unfortunately, because of the fast pace of events, I inadvertently briefed the Vice President Elect and others with incomplete information regarding my phone calls with the Russian Ambassador,” he wrote. “I have sincerely apologized to the President and the Vice President, and they have accepted my apology.”

The White House said in the statement that it was replacing Mr. Flynn with retired Lt. General Joseph Keith Kellogg, Jr., a Vietnam War veteran, as acting national security adviser.

...The White House has examined a transcript of a wiretapped conversation that Mr. Flynn had with Sergey I. Kislyak, the Russian ambassador, in December, according to administration officials. Mr. Flynn originally told Mr. Pence and others that the call was limited to small talk and holiday pleasantries.

But the conversation, according to officials who have seen the transcript of the wiretap, also included a discussion about sanctions imposed on Russia after intelligence agencies determined that Mr. Putin’s government tried to interfere with the 2016 election on Mr. Trump’s behalf. Still, current and former administration officials familiar with the call said the transcript was ambiguous enough that Mr. Trump could justify both firing or retaining Mr. Flynn.

Mr. Trump, however, has become increasingly concerned about the continued fallout over Mr. Flynn’s behavior, according to people familiar with his thinking, and has told aides that the media storm around Mr. Flynn would damage the president’s image on national security issues.

Intelligence analysts began to search for clues that could help explain Putin’s move. The search turned up Kislyak’s communications, which the FBI routinely monitors, and the phone call in question with Flynn, a retired Army lieutenant general with years of intelligence experience.

From that call and subsequent intercepts, FBI agents wrote a secret report summarizing ­Flynn’s discussions with Kislyak.

In the waning days of the Obama administration, James R. Clapper Jr., who was the director of national intelligence, and John Brennan, the CIA director at the time, shared Yates’s concerns and concurred with her recommendation to inform the Trump White House. They feared that “Flynn had put himself in a compromising position” and thought that Pence had a right to know that he had been misled, according to one of the officials, who, like others, spoke on the condition of anonymity to discuss intelligence matters.