Questioned by a federal judge in Manhattan, Cohen indicated he had paid sums of $130,000 and $150,000 each to two women who claimed they had affairs with Trump, at his boss's request in order to buy their silence "with the purpose of influencing the election".
Separating Cohen's guilty plea by minutes, was the Manafort verdict.
Donald Trump's former campaign chief Paul Manafort was found guilty of fraud Tuesday, in the first trial resulting from the investigation into Russian meddling in the 2016 presidential election.
While the jury was unable to reach a verdict on 10 counts, prompting the judge to declare a partial mistrial, Manafort was found guilty on the eight remaining charges.
US President Donald Trump expressed regret after a jury found his former campaign chairman Paul Manafort guilty on fraud charges, describing him as a "good man".
"I feel very sad about that," Trump told reporters as he arrived in West Virginia for a rally, claiming the conviction was part of a "witch hunt" after the 2016 election.
Trump expressed regret, but also sought to distance himself from Manafort - who was instrumental in the 72-year-old securing the 2016 Republican nomination.
"He worked for many, many people," said Trump, citing campaigns for former president Ronald Reagan and vice presidential candidate Bob Dole.
"It's a very sad thing that happened, this has nothing to do with Russian collusion."