The US attorney general has said he “personally approved” to seek a search warrant on Donald Trump’s Florida residence.
In a statement made in Washington DC, Merrick Garland said the Justice Department did “not take the decision lightly”.
He confirmed that federal agents searched Mr Trump’s Mar-a-Lago estate in Palm Beach on Monday to probe whether he illegally removed records from the White House as he was leaving office.
The Justice Department has faced pressure since the raid to provide a public explanation for the search.
Mr Garland added that the department has asked a court to unseal the search warrant, due to “substantial public interest” and have requested to make public the property receipt detailing what agents found inside the estate.
Mr Trump announced the search himself in a statement on Monday, claiming that agents had broken into his safe and said it represented “dark times for our nation”.
In response to Mr Garland’s remarks, Mr Trump said on social media platform Truth Social that his attorneys and representatives were “cooperating fully”.
He added that the government could have had “whatever they wanted, if we had it” and that “very large numbers of agents” raided Mar-a-Lago.
“They got way ahead of themselves. Crazy,” he said.
Following the unprecedented search, the Justice Department has faced fierce criticism, with Trump supporters, and some of his fellow Republicans in Washington accusing Democrats of weaponising the federal bureaucracy to target Mr Trump.
The US Justice Department has been investigating the discovery of boxes of records containing classified information that were taken to Mar-a-Lago after Mr Trump’s presidency ended.
They were retrieved in January by the National Archives and Records Administration (NARA), which then asked the Justice Department to examine whether Mr Trump’s handling of White House records violated federal law.
It noted that some of the boxes contained items “marked as classified national security information”.
It is not clear what law enforcement officials were looking for, but it is likely to have been any additional evidence that would help with prosecutors’ case.
They are trying to prove that Mr Trump or his aides intentionally broke the law.
That would mean producing evidence that shows the Trump camp were told taking the documents was not allowed.
Analysis – Sky reporter David Blevins
The attorney general was under pressure to justify the execution of a search warrant at the home of the former president.
Donald Trump’s claim that the operation was politically motivated has been gaining momentum among his Republican allies.
But Merrick Garland had to walk a fine line between defending the decision to seek a warrant and protecting the integrity of the investigation.
The Department of Justice has filed a motion to unseal the search warrant and that would place much more information in the public domain.
In taking personal responsibility for the decision, the attorney general issued a staunch defence of the FBI and justice department.
Amid criticism and even threats on social media, he said: “I will not stand by silently while their integrity is unfairly attacked.”
Hours earlier, a man had opened fire with a nail gun before pointing a rifle in an FBI office in Cincinnati, Ohio but no motive has been established.