Jan. 6 riot was fueled by Trump's 'lies' about 2020, special counsel alleges after 3rd indictment

Shortly after a third indictment was unveiled against former President Donald Trump, prosecutor Jack Smith spoke briefly on Tuesday from the Department of Justice about the new charges related to Trump's efforts to overturn his 2020 election loss.

Smith said that the Jan. 6 attack on the U.S. Capitol was "an unprecedented assault on the seat of American democracy" that was "fueled by lies" from the former president about the 2020 election.

"The indictment was issued by a grand jury of citizens here in the District of Columbia and it sets forth the crimes charged in detail," Smith said. "I encourage everyone to read it in full."

Trump faces four charges: conspiracy to defraud the United States, conspiracy to obstruct an official proceeding, obstruction of and attempt to obstruct an official proceeding and conspiracy against rights.

He has denied all wrongdoing and claimed political persecution. In a statement, his campaign contended that the new charges were part of a "witch hunt" that "will fail."

He has been ordered to appear on Thursday in federal court in Washington.

Smith, in his remarks, reiterated that Trump is presumed innocent until he is tried. "My office will seek a speedy trial so that our evidence can be tested in court and judged by a jury of citizens," Smith said.

The Justice Department, he said, is dedicated to holding accountable those people who were responsible for the Jan. 6 attack and that the case against Trump is an example of that commitment.

Smith added that the department's investigation into other people connected to the case is ongoing.

In a separate event on Tuesday, Attorney General Merrick Garland, who appointed Smith as the independent special counsel to investigate Trump, praised Smith and the other officials working with him.

"Mr. Smith and his team of experienced, principled career agents and prosecutor have followed the facts and the law wherever they lead," Garland said. "Any questions about this matter will have to be answered by the filings made in the courtroom."

ABC News' Alexander Mallin contributed to this report.