US House Speaker Nancy Pelosi (D-CA) announced Thursday that she will step down after two decades as the Democratic Party’s leader in the chamber.

“With great confidence in our caucus I will not seek re-election to Democratic leadership in the next Congress," Pelosi said in a speech on the House floor, as quoted by NBC News.

Pelosi was speaker from 2007 to 2011 and returned to the job in 2019. She announced her decision a day after Republicans regained control of the House, sending Pelosi and the Democrats back to the minority.

Pelosi will not be leaving Congress after winning her 19th term last week.

Pelosi's decision is expected to kick off a wave of generational change in Democratic leadership. House Majority Leader Steny Hoyer, 83, also announced Thursday that he will not seek another term in leadership, reported NBC.

Majority Whip James Clyburn of South Carolina, 82, will not seek any of the top three spots in leadership, but has indicated that he plans to stay on in an “advisory” role.

"For me, the hour’s come for a new generation to lead the Democratic Caucus that I so deeply respect and I’m so grateful that so many are ready and willing to shoulder this awesome responsibility," Pelosi said in Thursday’s speech.

"I have enjoyed working with three presidents achieving historic investments in clean energy with President George Bush, transformative health care reform with President Barack Obama and forging the future from infrastructure to health care to climate action with President Joe Biden," Pelosi added, while failing to mention Donald Trump.

President Joe Biden spoke with Pelosi Thursday morning and congratulated her on her historic tenure as speaker, the White House said.

"Because of Nancy Pelosi, the lives of millions and millions of Americans are better, even in districts represented by Republicans who voted against her bills and too often vilify her," the president said in a statement. "That’s Nancy — always working for the dignity of all of the people."

The race to succeed Pelosi is expected to feature a series of next-generation candidates. Hakeem Jeffries of New York, 52, the Democratic Caucus chairman, has been considered Pelosi’s heir apparent.

Pelosi has not indicated who she would like to see replace her as leader, but Hoyer and Clyburn both endorsed Jeffries on Thursday.

Pelosi’s decision comes weeks after her husband, Paul, was attacked by a man who broke into the Pelosi home in California, and assaulted Paul with a hammer upon discovering the Speaker was not at home.

The Speaker recently indicated in an interview with CNN that the attack on her husband will affect her decision on whether to retire, should the Democrats lose control of the House in the midterm elections.