Donald Trump's former personal lawyer, Michael Cohen, has pleaded guilty to tax fraud, campaign finance violations and bank fraud in federal court in New York.
Cohen appeared in court after he agreed to a plea bargain with federal prosecutors.
The 51-year-old lawyer's voice cracked as he answered questions from Judge William Pauley III.
Cohen pleaded guilty to five counts of tax fraud, one count of making false statements to a financial institution, one count of willfully causing an unlawful corporate campaign contribution and one count of making an excessive campaign contribution.
He said he arranged to make payments "for (the) principal purpose of influencing (the) election" at the direction of a candidate for federal office but did not give the candidate's name.
The judge has set 12 December for sentencing and set bail at $500,000.
An attorney for Cohen said Mr Trump directed Cohen to commit a crime.
"Today he stood up and testified under oath that Donald Trump directed him to commit a crime by making payments to two women for the principal purpose of influencing an election," Cohen's attorney Lanny Davis said in a statement.
"If those payments were a crime for Michael Cohen, then why wouldn't they be a crime for Donald Trump?" Mr Davis said.
Federal prosecutors in New York began investigating Cohen after a referral from US Special Counsel Robert Mueller.
Mr Mueller has been investigating Russian meddling in the 2016 election and possible coordination with the Trump campaign.
Mr Trump has repeatedly denied any collusion and has called the Mueller investigation a witch-hunt.
Russia has denied meddling in the election. US intelligence agencies have concluded that Russia did interfere.
Mr Cohen was part of Mr Trump's inner circle for more than a decade, working as his personal attorney at the Trump Organisation and continuing to advise the president after the election. But their relationship has frayed in recent months.
Federal agents had seized documents and files from Cohen in April that stemmed from a referral from Mr Mueller's office.
Cohen once said he would "take a bullet" for Mr Trump, but their relationship has deteriorated since an FBI raid on Cohen's office, hotel room and home in April.
The New York Times reported on Sunday that federal prosecutors were focused on more than $20 million in loans obtained by Cohen from taxi businesses owned by him and his family.
The loans are part of the investigation into whether Cohen committed bank and tax fraud, and for possible campaign law violations linked to a $130,000 payment to adult film star Stormy Daniels.
Mr Mueller's investigation, which began in May 2017, has resulted in the indictment of more than 30 people and five guilty pleas.
