By Susan Heavey and Sarah N. Lynch
WASHINGTON (Reuters) - As President Donald Trump took part in the Group of 20 summit in Argentina on Friday, pressure on him was building back in Washington from Special Counsel Robert Mueller's long-running investigation into Russian meddling in U.S. politics.
Trump's former campaign chairman, Paul Manafort, accused of lying to investigators, may face additional legal charges, U.S. prosecutors said on Friday, as Trump defended his 2016 business dealings in Russia while he was a presidential candidate as "very legal & very cool."
Mueller is looking into Russian interference in the 2016 U.S. presidential election, possible collusion between Moscow and Trump's campaign, and possible obstruction of justice.
For most of his presidency, Trump has been shadowed by the investigation, which he has angrily dismissed as a "witch hunt" amid concerns in Congress that he might move to fire Mueller, triggering a constitutional crisis.
Legislation to protect Mueller has been proposed, but blocked by Senate Republican leader Mitch McConnell.
More From This Section
At a court hearing on Friday, Mueller's team said new charges were possible against Manafort, one of numerous Trump associates swept up in the investigation.
Manafort has pleaded guilty to conspiracy against the United States and been convicted separately of bank and tax fraud. He had agreed to cooperate with Mueller but prosecutors have since accused him of breaching his plea deal by lying to investigators. He has said he disagrees with that accusation.
Whether new charges against him will follow has not been determined, a member of Mueller's team said in court.
On Thursday, Trump's former personal lawyer Michael Cohen pleaded guilty to lying to Congress about a proposed Trump skyscraper deal in Moscow that was never built.
In his plea, Cohen said efforts to pursue the project lasted longer, going deep into the 2016 U.S. presidential campaign, than he had previously told Congress. He said those efforts did not cease until June 2016, after Trump had effectively clinched the Republican presidential nomination.
In early-morning Twitter messages from Buenos Aires, Trump said he had "lightly looked" at a real estate project "somewhere in Russia" during his presidential bid, saying it was "very legal & very cool" to do so while campaigning.
During the 2016 presidential campaign, Trump repeatedly played down his business ties with Russia.
The Kremlin has denied U.S. intelligence agencies' findings that it meddled in the 2016 election. Both Russia and Trump have denied any collusion between them occurred.
Mueller's team has brought charges or secured convictions against more than two dozen Russian nationals and entities, as well as a number of Trump's associates.
Democrats and other critics said the latest revelations from Mueller's investigation showed Trump put his business interests above his obligation to speak truthfully to voters.
"The walls are beginning to close in. This begins to show reasons for the president and his campaign colluding with the Russians," said Representative Jerry Nadler, who is expected to become chairman of the House of Representatives Judiciary Committee when Democrats take control of the House in January.
After Cohen's guilty plea on Thursday, Trump canceled his planned meeting with Russian President Vladimir Putin at the G20, citing the Ukraine crisis.
White House spokeswoman Sarah Sanders said Mueller's investigation is probably undermining ties with Russia, but she denied it was the reason Trump canceled the meeting.
(Additional reporting by Susan Cornwell; Writing by Andy Sullivan; Editing by Kevin Drawbaugh and Bill Trott)