Lev Parnas, the Soviet-born businessman who played a central role in the campaign to pressure Ukraine to investigate political rivals of President Trump, completed his break with the White House on Wednesday, asserting for the first time in public that the president was fully aware of the efforts to dig up damaging information on his behalf.

Attorney Richard Painter, who served as the chief White House ethics lawyer in the George W. Bush administration, warned on Thursday that President Donald Trump appeared to be committing "felony bribery" by giving Republican senators fundraising cash ahead of an increasingly likely impeachment trial in the Senate.

President Trump told a crowd of staff from the United States Mission to the United Nations on Thursday morning that he wants to know who provided information to a whistle-blower about his phone call with the president of Ukraine, saying that whoever did so was “close to a spy” and that “in the old days,” spies were dealt with differently.

As federal prosecutors in Manhattan gathered evidence late last year about President Trump’s role in silencing women with hush payments during the 2016 campaign, Mr. Trump called Matthew G. Whitaker, his newly installed attorney general, with a question. He asked whether Geoffrey S. Berman, the United States attorney for the Southern District of New York and a Trump ally, could be put in charge of the widening investigation, according to several American officials with direct knowledge of the call.

A lawyer for President Trump broached the idea of Mr. Trump pardoning  two of his former top advisers, Michael T. Flynn and Paul Manafort, with their lawyers last year, according to three people with knowledge of the discussions.