Biden blames staff for documents found at his home

US President Joe Biden has blamed his staff for doing a bad job of checking to make sure no classified documents were included as they packed up his papers after he left his role as vice-president in President Barack Obama's administration.

Biden told PBS' Judy Woodruff in an interview broadcast Wednesday: "What was not done well is, as they packed up my offices to move them, they didn't do the kind of job that should have been done to go thoroughly through every single piece of literature that's there."

The president went into detail for the first time about what was in the documents that were found at his residence and at an office connected to him. All the documents were related to his time as vice-president and while he was in the Senate.

"The best of my knowledge, the kind of things they [investigators] picked up, are things from 1974, stray papers. There may be something else, I don't know," Biden said.

In 1974, Biden was in his second year in the US Senate.

Biden's executive assistant Kathy Chung was responsible for packing up his office and ensuring that no classified documents were included in the move after his time as vice-president ended.

Chung was helped by others of a lower rank. Investigators have spoken to her to learn more about what happened during the move, The Wall Street Journal reported.

Special counsel to the president Richard Sauber revealed that Biden's lawyers first discovered a batch of 10 classified documents in a "locked closet" on Nov 2, while cleaning out an office formerly used by the president.

The documents were found at the Penn Biden Center in Washington DC, a think tank Biden helped create with the University of Pennsylvania. The discovery was only made public last month.

On Nov 4, the Archives informed the Justice Department about the classified documents. On Nov 9, the FBI assessed whether they had been mishandled.

The discovery led to more searches. The White House then confirmed that it had found one, then five more pages of classified documents in Biden's personal library at his Wilmington, Delaware, home. Other documents were found in his garage.

The discovery of the classified documents led Attorney General Merrick Garland to appoint Robert Hur as special counsel on Jan 12, to investigate if the documents had been mishandled while at the various locations.

Biden said he was "surprised" at the discovery but gave little more detail.

During the interview with Woodruff, Biden erred on the side of caution about revealing too much but said he was cooperating fully with the investigation.

He added: "No one's had to threaten to do anything," because we "opened every single aperture I have in the house, offices, everything".

Last week, federal agents searched Biden's beach house in Rehoboth, Delaware, but said they didn't find any other classified documents.

Bidens said in the interview: "I'll just let the investigation, you know, decide what's going on and we'll see what happens."

The discovery of the documents marked classified have been an embarrassment to Biden after he criticized former president Donald Trump as "totally irresponsible" for having dozens of documents marked classified at Trump's Mar-a-Lago estate in Florida.

The FBI raided Trump's estate in August after attempts to recover them were rebuffed.

Biden was quick to separate the discovery of the sensitive material in his possession from the FBI's seizure of documents at Trump's estate during his PBS interview. He also explained his comments about Trump.

"What they've informed me not to speak to this issue to anyway, try to prejudice the investigation that's going on. But what I was talking about [on Trump] was what was laid out. All these documents were a top secret, code word and all the rest."

The Republican-led House Committee on Oversight and Accountability has launched its own investigation into Biden.