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.

Manhattan District Attorney Alvin Bragg on Friday again resisted the House GOP investigation of his office’s prosecution of Trump.

Bragg’s legal counsel called the inquiry “illegitimate incursion” into a legitimate investigation.

The House Republicans -- Reps. Jim Jordan, James Comer and Bryan Steil -- have said they want to find evidence of federal funds used to investigate Trump. But Bragg’s office said they were merely doing Trump’s bidding.

“Finally, as you are no doubt aware, former President Trump has directed harsh invective against District Attorney Bragg and threatened on social media that his arrest or indictment in New York may unleash 'death & destruction.' As Committee Chairmen, you could use the stature of your office to denounce these attacks and urge respect for the fairness of our justice system and for the work of the impartial grand jury," counsel Leslie Dubeck wrote in a letter to the lawmakers.

"Instead, you and many of your colleagues have chosen to collaborate with Mr. Trump’s efforts to vilify and denigrate the integrity of elected state prosecutors and trial judges and made unfounded allegations that the Office’s investigation, conducted via an independent grand jury of average citizens serving New York State, is politically motivated.”