Photo by Win McNamee/Getty Images

House Speaker Nancy Pelosi is ready to transmit the articles of impeachment to the Senate, after sitting on the documents for three weeks. Pelosi said she will transmit the articles next week.

The House Democrats voted unanimously to impeach President Donald Trump in December. But Pelosi delayed sending the articles of impeachment to the Senate for the second phase of the impeachment process - the trial.

In a letter to her Democratic colleagues on Friday, Pelosi said she asked Judiciary Committee Chairman Jerry Nadler to prepare a resolution to appoint managers to transmit the articles of impeachment next week.

Pelosi was under increasing pressure from both sides of the aisle to transmit the articles, after she claimed impeaching Trump was "urgent" and "necessary" to preserve the legitimacy of the 2020 elections.

Photo by Win McNamee/Getty Images

The House has no control over the Senate trial, but Pelosi refused to send the documents until Senate Majority leader Mitch McConnell advised her of the steps he would take to try Trump. Pelosi is pictured with McConnell in a photo dated Dec. 8, 2016.

"Every Senator now faces a choice: to be loyal to the President or to the Constitution," Pelosi wrote in the letter to her colleagues. "No one is above the law, not even the President."