WASHINGTON -- Sen. Elizabeth Warren on Monday took the first major step toward launching a widely anticipated campaign for the presidency, hoping her reputation as a populist fighter can help her navigate a Democratic field that could include nearly two dozen candidates.

"No matter what our differences, most of us want the same thing," the 69-year-old Massachusetts Democrat that highlights her family's history in Oklahoma. "To be able to work hard, play by the same set of rules and take care of the people we love. That's what I'm fighting for and that's why today I'm launching an exploratory committee for president."

Warren burst onto the national scene a decade ago during the financial crisis with calls for greater consumer protections. She quickly became one of the party's more prominent liberals even as she sometimes fought with Obama administration officials over their response to the market turmoil.

Now, as a likely presidential contender, she is making an appeal to the party's base. Her video notes the economic challenges facing people of colour along with images of a women's march and Warren's participation at an LGBT event.

In an email to supporters, Warren said she'd more formally announce a campaign plan early in 2019.

Warren is the most prominent Democrat yet to make a move toward a presidential bid and has long been a favourite target of President Donald Trump.

In mid-December, former Obama housing chief Julian Castro also announced a presidential exploratory committee, which legally allows potential candidates to begin raising money. Outgoing Maryland Rep. John Delaney is the only Democrat so far to have formally announced a presidential campaign.

But that's likely to change quickly in the new year as other leading Democrats take steps toward White House runs.

Warren enters a Democratic field that's shaping up as the most crowded in decades, with many of her Senate colleagues openly weighing their own campaigns, as well as governors, mayors and other prominent citizens. One of her most significant competitors could be Sen. Bernie Sanders, a Vermont independent who is eyeing another presidential run harnessing the same populist rhetoric.

She must also move past a widely panned October release of a DNA test meant to bolster her claim to Native American heritage. The move was intended to rebut Trump's taunts of Warren as "Pocahontas." Instead, her use of a genetic test to prove ethnicity spurred controversy that seemed to blunt any argument she sought to make. There was no direct mention of it in the video released Monday.

Speaking to reporters Monday outside her Cambridge, Massachusetts, home, Warren largely danced around a question on whether she wishes she had handled the DNA test release any differently.

"I have put it all out there. It's there for anyone to see," Warren said. "But at the end of the day ... this election going forward is going to be about the tens of millions of families across this country who work hard, who play to the rules and who just time after time take one body blow after another."

Trump told Fox News Channel's "All-American New Year" in an interview to be broadcast Monday night that he hopes Warren does run for president.

"We'll see how she does," he said. "I wish her well. I hope she does well. I'd love to run against her."

Warren has the benefit of higher name recognition than many others in the Democratic mix for 2020, thanks to her years as a prominent critic of Wall Street who originally conceived of what became the government's Consumer Financial Protection Bureau.

She now faces an arduous battle to raise money and capture Democratic primary voters' attention before Iowa casts its first vote in more than a year. She has an advantage in the $12.5 million left over from her 2018 re-election campaign that she could use for a presidential run.

Warren's campaign is likely to revolve around the same theme she's woven into speeches and policy proposals in recent years: battling special interests, paying mind to the nexus between racial and economic inequities.

"I run for office because I'm grateful down to my toes for the opportunities that were given to me, and I'm determined that we will give those same opportunities to not just some of our kids but to all of our kids," Warren said.

Associated Press writers Juana Summers in Washington, Alanna Durkin Richer in Cambridge, Mass., and Steve LeBlanc in Boston contributed to this report.