Stormy Daniels' lawyer, Clark Brewster, issued a statement on the indictment, saying: "The indictment of Donald Trump is no cause for joy. The hard work and conscientiousness of the grand jurors must be respected. Now let truth and justice prevail. No one is above the law."

While the indictment remains under seal, Trump had been under investigation by the Manhattan district attorney over a $130,000 payment he made to the adult film actress to keep her from going public with a claim of an affair, which he denies.

Donald Trump being formally accused of a crime could change the outlook for the still-forming field of Republican presidential candidates in 2024 -- either rallying primary voters primed by his talk of the "deep state" and "retribution" or opening up an unprecedented line of criticism for Trump's rivals.

The indictment itself isn't disqualifying, legally speaking. The U.S. Constitution doesn't prevent people under indictment or criminal investigation from running for the White House, experts have told ABC News, so the former president could still be reelected despite the indictment -- and would still be eligible even if it leads to a conviction, regardless of practical obstacles like potential incarceration.

ABC News has learned that former president Donald Trump has been indicted, according to multiple sources with knowledge. The charges were not immediately clear.

Manhattan District Attorney Alvin Bragg has notified Trump.

Trump's former attorney, Michael Cohen, said in a statement, "I do take solace in validating the adage that no one is above the law; not even a former President."

"Today’s indictment is not the end of this chapter; but rather, just the beginning," Cohen said. "Accountability matters and I stand by my testimony and the evidence I have provided to [the district attorney's office]."

The Manhattan grand jury weighing charges against former President Donald Trump will not convene on Wednesday and is expected to meet Thursday on other matters, sources familiar with the situation told ABC News.

The proceeding is conducted in secret and the grand jury could be presented with evidence or vote at any time.

While 45% of Americans believe former President Donald Trump should face charges in an investigation by the Manhattan District Attorney's Office, 32% say he shouldn't have been indicted, according to a new ABC News/Ipsos poll.

Another 23% of American say they don't know whether the nation's 45th president should face charges.

While the charges have not been announced, a Manhattan grand jury that indicted Trump had been hearing evidence in a $130,000 hush money payment Trump allegedly made to adult film actress Stormy Daniels, who claims they had an affair. Trump has denied the allegations.

The poll showed a split in opinions along party lines. While 88% of Democrats said Trump should face charges, 62%, of Republicans said the former president should not have been charged while 16% said he should be charged, and the remainder was uncertain.

About 47% of Americans polled say the charges are politically motivated, echoing the sentiment from top GOP figures. About 79% of Republicans hold that view.

-ABC News' Brittany Shepherd