Mexico City: US President Joe Biden said on Tuesday that he was unaware of the contents of classified documents from his time as vice president found at an office he used at a Washington think tank, expressing surprise at their discovery.
"People know I take classified documents, classified information seriously," he told reporters after a summit in Mexico City.
"I was briefed about this discovery and surprised to learn there were any government records that were taken there to that office. But I don't know what's in the documents," Biden said.
"We're cooperating fully with the review," he said, adding he hoped it would be completed soon.
Biden's special counsel Richard Sauber said on Monday that the president's lawyers discovered the documents last November while clearing out the office space and handed them over to the National Archives, which handles all such materials.
He described it as "a small number of documents with classified markings" that were found in a locked closet at the Penn Biden Center, a think tank affiliated with the University of Pennsylvania.
"The documents were not the subject of any previous request or inquiry" and since handing them over, Biden's attorneys have also cooperated "to ensure that any Obama-Biden Administration records are appropriately in the possession of the Archives," he said.
In August, authorities searched ex-president Donald Trump's residence at Mar-a-Lago after he failed to respond to repeated requests for cooperation on retrieving documents taken from the White House after his 2020 election loss.
The FBI found thousands of government documents, including more than 100 that were marked classified, and some marked top secret in the ex-president's Florida club. Subjects covered in the documents reportedly included sensitive intelligence on China and Iran, and nuclear secrets.