President Joe Biden said Tuesday he was “surprised” to learn that secret government records from his tenure as vice president had been stashed at a private office in his namesake think tank. He addressed the brewing scandal at a news conference in Mexico City, where he attended a trilateral North American Leaders’ summit with the heads of Mexico and Canada. “I was surprised to learn there were any government records that were taken there to that office," Biden said. "I don’t know what’s in the documents. My lawyers have suggested I not ask what they were ... we’re cooperating fully with the review, which I hope will be finished soon.” The documents—some apparently classified—were found in a "locked closet" at Biden’s former Washington think tank in November, his attorney, Richard Sauber said. The documents reportedly include “intelligence memos and briefing topics” on global topics including Ukraine, Iran and the United Kingdom, according to CNN.