Former Donald Trump campaign chairman Paul Manafort pleaded guilty to two criminal counts Friday in the latest legal victory for Special Counsel Robert Mueller.

U.S. District Judge Amy Berman Jackson agreed to the plea deal during a hearing at the D.C. federal courthouse. It allows Manafort to avoid a trial that was set to begin Monday and in exchange, could indicate his cooperation in Mueller's probe, which is seeking to determine whether Trump's campaign colluded with what U.S. officials have called a Russian influence campaign in the 2016 election.

Manafort was convicted in a separate case in August on charges that could bring an effective life sentence.

The charges he pleaded guilty to are related to his lobbying work for a pro-Russia Ukrainian political party. They include conspiracy against the United States, and conspiracy to obstruct justice. He faced a total of seven charges at court, and prosecutors dropped the additional five.

Manafort pleaded guilty to concealing millions of dollars from tax officials by funneling the funds into overseas accounts. "MANAFORT cheated the United States out of over $15 million in taxes," the criminal information states.

"Manafort laundered more than $30 million to buy property, goods, and services in the United States, income that he concealed from the United States Treasury, the Department of Justice, and others," the document states.

The document further states the Trump campaign chairman worked "to influence, delay and prevent the testimony of" two witnesses.

Manafort, a former political consultant with a lengthy history in Washington, had fought against Mueller's probe and earlier refused to cooperate.