On Monday, Biden’s lawyers confirmed that around 10 documents containing an unidentified number of classified materials were discovered at the Penn Biden Center for Diplomacy and Global Engagement in November. The president used the office space after the end of his vice presidency in 2017 until the beginning of his 2020 presidential campaign.

Biden was asked about the documents’ discovery at a press conference following the conclusion of the North American Leaders’ Summit in Mexico City, Mexico, on Tuesday, and told reporters that he “takes classified documents, classified information seriously.”

“I was briefed about this discovery and was surprised to learn there were any government records that were taken there to that office,” Biden said, according to a clip of his response that was posted by C-SPAN Tuesday evening.

“I don’t know what’s in the documents, my lawyers have not suggested I ask what documents they were,” the president continued. “They’ve turned over the boxes to the [National Archives and Records Administration (NARA)], and we’re cooperating fully.”

The White House said Monday that Biden’s lawyers immediately contacted NARA once discovering the documents, and the agency retrieved them the next morning and informed the Department of Justice (DOJ), which is reviewing the case.

Biden’s stunned reaction marks another contrast between this week’s report and the DOJ’s investigation of documents discovered at former President Donald Trump’s Mar-a-Lago home. The FBI searched the former president’s estate in August, retrieving more than 100 classified documents.

Following news of the FBI carrying out a search warrant of Trump’s home, the former president posted on his Truth Social account in August that the search was “not necessary or appropriate,” and called the raid “prosecutorial misconduct.”

Trump has also continued to denounce the DOJ’s criminal investigation, claiming that he had declassified all of the documents before they were moved from the White House. He also called the FBI’s taking of additional documents discovered in December “illegal.”

On Monday, the former president posted to Truth Social, asking, “When is the FBI going to raid the many homes of Joe Biden, perhaps even the White House? Those documents were definitely not declassified.”

Newsweek has reached out to the White House for comment.