Donald Trump has praised former Vice President Mike Pence just one day after Pence was issued with a subpoena as part of an investigation into the former president's handling of classified documents.

Trump gave an interview to Fox News Digital on Friday where he defended his former vice presidential running mate and later took to his Truth Social platform to criticize Special Counsel Jack Smith.

Smith, who is investigating Trump's handling of White House documents found at his Mar-a-Lago residence, issued a subpoena to Pence on Thursday after months of negotiations between investigators and Pence's legal team.

"Mike Pence is an honorable man," Trump told Fox News Digital as he went on to list topics he believed the special counsel's probe should be investigating - revisiting issues he's raised repeatedly, including Special Counsel Robert Mueller's investigation into Russian interference in the 2016 presidential election.

"Are they going to look for the people that spied on my campaign?" the former president asked.

On Truth Social, Trump also criticized the special counsel and appeared to defend former Vice President Pence.

"Will Trump Hating Prosecutor Jack Smith be investigating the FACT that they SPIED on my campaign, even as I was in the Oval Office, they Stuffed the Ballot Boxes (per 2000 Mules), used Covid to cheat, that the FBI pushed Twitter & Facebook around, causing massive voter disruption, and so much more?" Trump wrote.