Presidents do have the authority to declassify information, but this typically follows a process to ensure there are no associated security risks.
Former officials in the Trump administration have scoffed at the notion that the Republican leader could have issued a blanket order.
Bill Barr, Mr Trump’s former attorney general, has previously said the suggestion was “almost worse than taking the documents”.
“If in fact he sort of stood over scores of boxes, not really knowing what was in them and said: ‘I hereby declassify everything in here,’ that would be such an abuse,” said Mr Barr.
“And that shows such recklessness, it’s almost worse than taking the documents.”
According to The Washington Post, the details of the nuclear defences of an unnamed foreign country were among the documents FBI agents seized from Mar-a-Lago.
In his interview, Mr Trump defended storing documents at Mar-a-Lago, where he often entertains visitors.
Mr Trump pointed out that the property is manned by Secret Service agents, making a rare reference to himself as a former president. He has refused to concede his defeat to Mr Biden in the 2020 election.
“I think we had good security. As you know, we had a tremendous Secret Service. They are unbelievable people. And they are all over Mar-a-Lago, as happens to a former president,” he said.
He went on: “I hate to use the word ‘former,’ because I have a lot of problems with what happened.”