New York state court records showed that Trump, who is seeking to regain the presidency this year, filed the notice with a mid-level state appeals court known as the Appellate Division, but the underlying documents were not yet public.

Trump's lawyers did not immediately respond to a request for comment.

A criminal trial would be the first of a former U.S. president.

The New York Times and CNN said the appeal would challenge a gag order by Justice Juan Merchan blocking Trump from speaking publicly about potential witnesses, court staff, individual prosecutors and family members of the judge and Manhattan District Attorney Alvin Bragg, who brought the charges.

Merchan imposed the order after finding that some of Trump's statements were threatening, and expanded it to cover the family members after Trump disparaged the judge's daughter online.

Trump's campaign has said the order violates his right to free speech under the U.S. Constitution's First Amendment.

Trump is accused of covering up his former lawyer Michael Cohen's $130,000 payment to porn star Stormy Daniels in exchange for her silence before the 2016 presidential election about a sexual encounter she has said she had with Trump a decade earlier. Trump has denied any such encounter with Daniels, whose real name is Stephanie Clifford.

Trump, the Republican candidate challenging Democratic President Joe Biden in the Nov. 5 U.S. election, has pleaded not guilty to 34 counts of falsifying business records.

It is one of four criminal cases he faces. The others stem from efforts to overturn his 2020 election loss to Biden, and his handling of sensitive government documents after leaving the presidency in 2021. Trump has pleaded not guilty to all charges.

(Reporting by Luc Cohen in New York; Editing by Will Dunham)

By Luc Cohen