WASHINGTON -- U.S. President Donald Trump's former personal attorney has pleaded guilty to campaign finance violations and implicated Trump in a campaign coverup to buy the silence of women who said they had sexual relationships with him. Michael Cohen's admission has thrown Trump's presidency into crisis and raises questions about Trump's own legal jeopardy.

Cohen's plea in federal court in New York on Tuesday came at nearly the same moment that Trump's onetime campaign chairman, Paul Manafort, was convicted by a jury in Virginia of financial crimes. Manafort faces separate charges in September in the District of Columbia that include acting as a foreign agent.

The back-to-back blows resulted from the work of special counsel Robert Mueller, who is investigating Russia's attempts to sway voters in the 2016 election, including hacking Democrats' emails, and whether the Trump campaign may have co-operated.

Trump has repeatedly denounced the probe as a "witch hunt."

Cohen's lawyer, Lanny Davis, said Wednesday that Cohen has information "that would be of interest" to the special counsel. Davis said Cohen is not looking for a presidential pardon.

"My observation is that the topics relating to hacking and the crime of hacking ... that there are subjects that Michael Cohen could address that would be of interest to the special counsel," Davis said in a series of television interviews.

Trump soon , taking a shot at Cohen: "If anyone is looking for a good lawyer, I would strongly suggest that you don't retain the services of Michael Cohen!"

The night before, at a political rally in West Virginia, the president mostly ignored the legal developments and insisted that his administration was still "winning."

But there was no doubt that Cohen's acknowledgement of a co-ordinated payoff scheme puts Trump's presidency on the defensive.

"It's going to be hard for the president to try to discredit all this. It's circling him," said David Weinstein, a former federal prosecutor who is not involved in the case.

Cohen and Manafort played prominent roles in Trump's political rise in 2016.

Cohen was known as Trump's longtime private "fixer" and once he'd take a bullet for Trump. Cohen released a secretly recorded audio of Trump discussing a payout made via a third party to model Karen McDougal who says she had a sexual relationship with Trump in 2006.

Such a payment could be regarded as an illegal campaign expenditure if the money was clearly meant to influence the 2016 election.

In a deal with federal prosecutors, Cohen pleaded guilty to eight counts, including tax evasion. He could get about four to five years in prison at sentencing Dec. 12.

Manafort was convicted of eight felony counts, including charges of filing false tax returns and failing to report foreign bank accounts. Prosecutors will decide whether to retry him on 10 other charges.

Manafort was a well-connected Republican consultant and lobbyist who prosecutors say made $60 million in foreign money working for Russia-backed politicians in Ukraine. He was campaign chairman for months during the GOP nomination battle in 2016.

Trump said Tuesday the legal developments had nothing to do with Russian election interference and that he felt "badly for both" men. At the West Virginia rally, he focused on developments on trade, taxes, North Korea and his plans for a space force.

"Where is the collusion?" he asked.

His supporters chanted Trump's campaign staples "Drain the swamp!" and "Lock her up!"

The White House is trying to keep the focus on the November election, when control of Congress is at stake. Trump allies such as former strategist Steve Bannon seek to frame the election as a referendum on the potential impeachment of the president. Trump confidants have long argued that the president's fate in such a scenario would ultimately be more a matter of politics than law.

Also Tuesday, prosecutors and defence attorneys for former Trump national security adviser Michael Flynn agreed to postpone his sentencing after he pleaded guilty to lying to the FBI about his contacts with a Russian official, in a sign his co-operation was still needed in the Mueller probe.

Trump confidants are reasserting that it is the White House position that a president cannot be indicted. They are citing a 2000 opinion of the Justice Department's Office of Legal Counsel, which provides legal advice and guidance to executive branch agencies.

Trump's lawyers have said Mueller plans to adhere to that guidance, though Mueller's office has never independently confirmed that. There would presumably be no bar against charging a president after he or she departs the White House.

For many around Trump, Cohen has represented a greater threat than even the Russia investigation, drawing from Cohen's decade of working as the then-celebrity real estate developer's fixer.

An FBI raid on Cohen's New York office and hotel room in April rattled the president, who has complained publicly about what he felt was government overreach while privately worrying about what material Cohen may have had after working for the Trump Organization for a decade.

Those in Trump's orbit, including his lawyer Rudy Giuliani, have steadily ratcheted up attacks on Cohen, suggesting he was untrustworthy and lying about what he knew about Trump's business dealings. When Cohen's team produced a recording that the former fixer had made of Trump discussing a payment to silence a woman about an alleged affair, Giuliani sought to impugn Cohen's credibility and question his loyalty.

Trump stewed for weeks over the media coverage of the Manafort trial. Though the proceedings were not connected to Russian election interference, Trump has seethed to confidants that he views the Manafort charges as "a warning shot" from Mueller.

"What matters is that a jury found that the facts presented to them by the special prosecutor warranted a conviction of someone who surrounds the president," Weinstein said.

------

Superville reported from Charleston, West Virginia. Associated Press writers Catherine Lucey, Ken Thomas and Eric Tucker contributed to this report.