NEW YORK (CBSNewYork/AP) – President Donald Trump’s former attorney Michael Cohen has pleaded guilty to lying to Congress as part of special counsel Robert Mueller’s investigation into Russian interference in the 2016 presidential election, CBS News confirms.

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Cohen made a surprise court appearance Thursday in New York. He admitted to making false statements in 2017 to the U.S. Senate Select Committee on Intelligence about a plan to build a Trump Tower in Moscow, The Associated Press reported.

Before departing for the G20 summit in Argentina, Trump reacted to the news, calling Cohen “a weak person and not very smart.”

“He has himself a big prison sentence and he is trying to get a much lesser prison sentence by making up a story,” he added.

Cohen pleaded guilty in August to eight federal charges, including tax evasion, bank fraud and campaign finance violations.

In doing so, he said that Trump told him to arrange payments, before the 2016 election, to buy the silence of adult film actress Stormy Daniels and a former Playboy model who allege they had affairs with Trump.

READ: Michael Cohen Plea Agreement

Cohen also made headlines last month when he switched his voter registration back to the Democratic party.

(© Copyright 2018 CBS Broadcasting Inc. All Rights Reserved. The Associated Press contributed to this report.)