BOSTON (AP) — U.S. Sen. Elizabeth Warren isn't in any rush to endorse a candidate in the Democratic presidential primary.

"It's just not time for me to do that yet," the Massachusetts Democrat said Friday when asked about whether she planned to endorse.

Warren had words of support for Democratic presidential hopeful Vermont Sen. Bernie Sanders, however.

"Bernie is doing what Bernie always does — he's out there talking from the heart, raising the issues that he's raised for decades now," Warren said. "That's just who he is."

Warren made the comments during a holiday lighting ceremony in Melrose, The Boston Herald reported.

Warren's comments come after Hillary Clinton received a public embrace last week from 13 female Democratic senators. The one noticeable absence was Warren.

The event also underscored how Warren remains a major holdout for Clinton, who appeared alongside Boston Mayor Marty Walsh at a recent event in Faneuil Hall. Walsh, a fellow Democrat, has endorsed Clinton.

An endorsement from Warren, a hero to the liberal wing of the Democratic party, is a sought-after prize in the race.

After declining a draft movement from supporters who wanted her to run for president, Warren has played a major role in pushing the Democratic field to address economic inequality, college affordability and tougher regulations on Wall Street.

Warren was among a large group of female senators who urged Clinton to run for president in a private letter sent in 2013. She has been promoting a corporate tax overhaul recently and by withholding her endorsement, she maintains leverage among a Democratic field courting her support.

Many of Warren's supporters have gravitated to Sanders, who frequently says the nation's economic system is "rigged," a term often used by Warren.