Democratic Sen. Kamala Harris of California has announced she is running for president.

On Monday she joined a growing number of Democratic candidates vying to challenge President Donald Trump in the 2020 US presidential election.

"I'm running for president," she said. "Let's do this together."

Sen. Kamala Harris says she is running for president, adding to a growing number of Democratic candidates vying to challenge President Donald Trump in the 2020 US presidential election.

The Democratic senator from California made the announcement on Twitter on Monday, timing the announcement to Martin Luther King Jr. Day.

"I'm running for president," she tweeted. "Let's do this together."

Harris also discussed the announcement and King on ABC's "Good Morning America" on Monday.

"He was aspirational like our country was aspirational," she said. "We know that we've not yet reached those ideals, but our strength is that we fight to reach those ideals."

Harris' campaign website said she would not accept donations from corporate PACs, adding: "We don't have to accept a system that drowns out your voice."

The former California attorney general teased a run in numerous media appearances in recent weeks. Harris previously said she would mull the decision over the holidays and said she would take into account her family's thoughts.

After publishing a memoir, "The Truths We Hold: An American Journey," Harris embarked on a media blitz and offered the traditional nondenial denial to queries about her presidential ambitions.

"So, I'm pleased to announce on 'The View' that I'm not ready to make my announcement," Harris joked on ABC's "The View" on January 8. "I'm very tempted, but I'm not yet ready," she said.

flickr: Patricia Montes Gregory

Also earlier this month, Harris was said to have shuttered her state campaign committee, Harris for Governor 2026, and donated the remaining funds to different organizations, fueling rumors of a presidential run.

Harris made stops at several battleground states in the fall including Iowa, South Carolina, and Wisconsin in support of other Democrats during the 2018 midterm elections.

Her announcement follows similar ones from Sen. Elizabeth Warren of Massachusetts, Sen. Kirsten Gillibrand of New York, and former Housing and Urban Development Secretary Julián Castro.

Other figures thought to be likely to enter the race include Sen. Cory Booker of New Jersey, Sen. Bernie Sanders of Vermont, and former Rep. Beto O'Rourke of Texas.

Read more: What women eyeing a run for the White House can expect from voters and the media in 2020

Of Sens. Elizabeth Warren, Kamala Harris, Amy Klobuchar, and Kirsten Gillibrand, only Klobuchar, second from right, has yet to announce a 20202 presidential bid. Jonathan Bachman/Reuters; Scott Applewhite/AP; Chip Somodevilla/Getty Images; Jacquelyn Martin/AP; Samantha Lee/Business Insider

Harris is serving her first term in the Senate. Before that, Harris was California's attorney general and served as the district attorney of San Francisco.

Harris most recently made headlines for her intense line of questioning during the confirmation hearings for Brett Kavanaugh's nomination to the Supreme Court.

The former prosecutor, who now sits on the Senate Judiciary Committee, demanded that the FBI thoroughly investigate the sexual-misconduct allegations made by Christine Blasey Ford, whose claims threatened to tank Kavanaugh's nomination.

During a December episode of MSNBC's "Morning Joe," Harris predicted what it would be like mounting a presidential campaign as a woman of color.

"Let's be honest — it's going to be ugly," Harris said.

"When you break things, it is painful. And you get cut. And you bleed."