Sen. Kamala Harris (D-Calif.) will formally announce her bid for the White House on or around Martin Luther King Jr. Day, sources told KCBS Radio, a station in her home state of California.

The sources said she would "probably" make the announcement at a rally in Oakland, the radio station added.

A spokesperson for Harris told The Hill, however, that no announcement is imminent and Harris will not be in Oakland during the holiday weekend.

Harris has long been considered a possible front-runner for the 2020 Democratic nomination, and speculation that she would enter the race continued to mount this week when she launched a book tour and media blitz to promote her memoir that was published Tuesday.

The KCBS Radio report comes after Harris told CNN's Jake Tapper on Wednesday that she will soon make a decision on whether to run in 2020.

During the CNN appearance, Harris said she thinks the U.S. is ready for a woman of color to be president.

"We have to give the American people more credit, and we have to understand that the American public and the people of our country are smart people who will make decisions about who will be their leader based on who they believe is capable, who they believe has an honest desire to lead, to represent, to see them, to be a voice for them even if they have no power," Harris said in the appearance.

Harris last month said that she planned to decide whether to run "over the holiday."

"It will ultimately be a family decision," she said at the time. "And over the holiday, I will make that decision with my family."

If Harris is the next major candidate to announce a bid, she would join Sen. Elizabeth Warren (D-Mass.) as the major Democratic names to have thrown their hats in the ring.

Warren last month announced an exploratory committee for a presidential bid.

Other possible high-profile Democratic candidates include Sens. Cory Booker (D-N.J.), Kirsten Gillibrand (D-N.Y.) and Bernie Sanders (I-Vt.), as well as former Vice President Joe Biden and former Rep. Beto O'Rourke (D-Texas).

Reid Wilson contributed to this report, which was updated at 9:03 a.m.