US Attorney General William Barr submitted his resignation letter on Monday to President Donald Trump. Trump posted the letter on Twitter shortly afterwards.

In his letter, Barr praised Trump’s accomplishments. As Trump’s second attorney general, he launched a probe of the 2016 Russia investigation, deterred asylum seekers, and attempted to punish protesters and cities for unrest during the summer protests. However, he refused to support Trump’s claims that the 2020 election was rigged. At one point, he directly contradicted Trump’s claims and declared that the Justice Department had not found any signs of widespread voter fraud. Reportedly, this strained the relationship between Barr and Trump, and Barr was considering resigning before mid-January. Further, some have speculated that his resignation is not entirely voluntary.

Barr’s tenure has been filled with controversy. He has frequently been criticized for politicizing the department and undermining its reputation. For example, his interference with Roger Stone‘s sentence drew criticism from Democrats and Republicans alike. For this and other instances, in February 2019, more than 2,000 former prosecutors and other DOJ officials signed a letter calling for him to resign.

He will remain in office until December 23 to wrap up a few matters.