US attorney general Jeff Sessions has abruptly agreed to recuse himself from any investigation into Russian meddling in America's 2016 presidential election amid growing pressure over his meetings with the Russian ambassador.
He acted after it emerged that he twice spoke with ambassador Sergey Kislyak during the campaign and failed to say so when pressed by Congress.
Mr Sessions rejected any suggestion that he tried to mislead anyone about his contacts with the Russian, saying: "That is not my intent. That is not correct."
But he did admit he should have been more careful in his evidence during his confirmation hearing, saying: "I should have slowed down and said, 'But I did meet one Russian official a couple of times'."
The White House has stood by Mr Sessions in the latest controversy to dog President Donald Trump's young administration, although officials said they first learned about his contacts with the ambassador from a reporter on Wednesday night.
Mr Trump said he had "total" confidence in Mr Sessions and did not think he needed to recuse himself - not long before he did.
One of the conversations with Mr Kislyak occurred at a July event on the sidelines of the Republican National Convention in Cleveland. At the same event, the ambassador also spoke with Carter Page, who briefly advised Mr Trump's campaign on foreign policy, according to a source.
Separately, a White House official said Mr Trump's son-in-law, Jared Kushner, met Mr Kislyak with ousted national security adviser Michael Flynn at Trump Tower in New York in December.
The official described that sit-down as a brief courtesy meeting. Mr Flynn was fired last month for misleading vice president Mike Pence about his contacts with Mr Kislyak.
The Trump team's account of Mr Flynn's contacts with the ambassador has changed several times. The White House did not disclose the in-person meeting, or Mr Kushner's involvement, until Thursday.
Mr Trump has been trailed for months by questions about potential ties to Moscow, and allegations of Russian efforts to interfere in the US election to help him defeat Hillary Clinton.
The new president and his campaign officials have blamed such contentions on Democratic sore losers and have denied any contact with Russians concerning the election.
While there is nothing necessarily nefarious or even unusual about a member of Congress meeting a foreign ambassador, typically members of the Senate Foreign Relations Committee meet foreign ambassadors, not Armed Services Committee members, such as Mr Sessions, whose responsibility is oversight of the military and the Pentagon.
The latest development comes on the heels of what had been the high point of Mr Trump's young presidency: a well-received address to Congress on Tuesday night that energised Republicans and appeared to wipe away some legislators' concerns about the administration's tumultuous start.
But Mr Sessions faced a rising chorus of demands that he resolve the seeming contradiction between his two conversations with Mr Kislyak and his sworn statements to Congress in January, when he said he had not had communications with Russians during the campaign.
The Justice Department said he met Mr Kislyak in his role as a member of the Senate Armed Services Committee, not in his role as a Trump adviser with the campaign, and that led to his answers.
The attorney general, an early backer and key adviser for Mr Trump's campaign, said he decided to recuse himself for investigations that are under way and others to come after his staff recommended he do so.
Acting deputy attorney general Dana Boente will handle such matters for now.
Mr Sessions added that his announcement "should not be interpreted as confirmation of the existence of any investigation".
Some Democrats called for Mr Sessions not only to recuse himself but to resign. House minority leader Nancy Pelosi, who had accused him of "lying under oath", repeated her call for his resignation after he recused himself.