Trump had filed an appeal to block a lower court's decision that had ordered Pence to testify. However, the U.S. Circuit Court of Appeals in Washington refused to block Pence's subpoena.

Trump could still appeal to the Supreme Court, but he has not indicated whether he will do so.

The special counsel Jack Smith, appointed by Attorney General Merrick Garland to investigate Trump's role in the January 6th events and his handling of classified documents after leaving office, issued Pence's subpoena.

Initially, Pence had argued that he was immune from testifying under the "speech or debate" clause of the Constitution. However, a federal judge ordered him to testify, disagreeing with his claim of immunity.

Smith has also issued subpoenas to top county election officials in swing states and 19 aides and allies of Trump who were allegedly involved in attempts to overturn the 2020 election.

In March, a federal judge had ruled that several of Trump's former aides, including Mark Meadows, Dan Scavino, and Stephen Miller, must testify. (ILKHA)