Some White House documents recovered from Mar-a-Lago were marked classified, National Archives confirms

The National Archives and Records Administration confirmed Friday that items marked "classified" were among the 15 boxes of White House records retrieved from former President Donald Trump's home, Mar-a-Lago, last month.

The National Archives also noted that the Trump administration "did not fully capture" all social media posts made by the ex-president and his White House staffers.

The disclosures came in two letters sent to the House Oversight and Reform Committee by U.S. Archivist David Ferriero. The Washington Post first reported last week that some of the records retrieved from Mar-a-Lago were clearly marked as classified.

In one letter, Ferriero said the Archives "has identified items marked as classified national security information within the boxes."

The discovery of those classified documents in Trump's Palm Beach, Fla., home prompted NARA staff to reach out to the Department of Justice, Ferriero told Oversight Chair Carolyn Maloney, D-N.Y., in that letter.

All 15 of those boxes should have been handed over to the National Archives directly from the White House once Trump left office in January 2021, as required by law, the agency has noted.

The Presidential Records Act requires that all applicable materials — such as documents, photos, correspondence and pamphlets — must be preserved and transferred to the National Archives as soon as the president leaves office.

Ferriero's letter also said the Archives "has identified certain social media records that were not captured and preserved by the Trump Administration," and that "some White House staff conducted official business using nonofficial electronic messaging accounts that were not copied or forwarded into their official electronic-messaging accounts" as required by law.

A spokeswoman for Trump did not immediately respond to CNBC's request for comment.

Prior administrations have had Presidential Records Act violations, and past presidents have had to return items that were taken after leaving the White House. But the volume of records removed from Mar-a-Lago is atypical, the Post and other news outlets have reported.

Former White House officials also have recently shed light on Trump's routine habit of ripping up documents.

The Post, which first reported on NARA's retrieval of the records from Mar-a-Lago and its referral to the Justice Department, has reported the boxes included a letter to Trump from former President Barack Obama, as well as Trump's self-described "love letters" with North Korean dictator Kim Jong Un.