Trump was recorded and said he knew he had a classified document.

Mr. Trump burst into tears over General Milley.

“Isn’t it great, I have a big stack of papers,” Trump said at one point. Papers could be heard rustling, and then Mr. Trump seemed to point to a specific document and say, “Look, this was him.” At another point he said, “This was the Defense Department and him.”

He described something in front of him as “like, very confidential,” insisting that it was really General Milley who wanted to attack Iran (in fact, General Milley warned against such a move).

At one point Mr. Trump was interrupted and a woman could be heard in the room on the recording referring to Hillary Clinton, the former Secretary of State whose email server Mr. Trump used as a line of attack during the 2016 presidential campaign. Mr. Trump said Mrs. Clinton would send material “to Anthony Weiner, that pervert,” referring to the former congressman who was married to an aide to Mrs. Clinton’s.

Mr. Trump and his allies have repeatedly claimed that, while still in office, he released all the material he took from the White House (although the charges may not depend on whether anything was classified). But his claim seemed to be undermined by the recording.

“As president I could have declassified them, now I can’t,” Trump said, according to the person familiar with the content. He then repeated that there was something “secret” when he and one of the women in the room were talking at once, according to the person familiar with its contents.

“Isn’t that interesting? It’s so cool,” Mr. Trump said, adding, “You probably almost didn’t believe me, but now you believe me.”