Former United States President Donald Trump has called for the “immediate” release of the federal warrant the FBI used to search his Florida estate, hours after the Department of Justice (DoJ) asked a court to unseal the warrant, with Attorney General Merrick Garland citing the “substantial public interest in this matter”.

In messages posted on his Truth Social platform late on Thursday, Trump wrote, “Not only will I not oppose the release of documents … I am going a step further by ENCOURAGING the immediate release of those documents.”

He continued to assail the FBI search of Mar-a-Lago as “unAmerican, unwarranted and unnecessary”.

“Release the documents now!” he wrote.

At a brief news conference earlier, Garland had defended the FBI search conducted this week at Trump’s Mar-a-Lago home, saying he personally approved it and adding the DoJ did not take searching citizens’ homes lightly and would employ “less intrusive” means where possible.

Garland told reporters the DoJ has asked a federal judge to unseal the court-approved warrant that enabled the search and the property receipt relating to it.

“The department filed the motion to make public the warrant and receipt in light of the former president’s public confirmation of the search, the surrounding circumstances and the substantial public interest in this matter,” Garland said.

The attorney general, who was appointed by President Joe Biden, did not provide details about the nature of the investigation that led to the search of Mar-a-Lago on Monday night.

Several US media outlets earlier cited unidentified sources as saying that the inquiry was looking into possible mishandling of classified material, and on Thursday, The Washington Post reported that the agents were looking for documents related to nuclear weapons.

The Post said it was not clear whether such documents had been found.

Some 10 boxes of material were retrieved from Mar-a-Lago, the Reuters news agency said, citing an unnamed source.

It is unclear at this point how much information would be included in the documents, if made public, or if they would encompass an FBI affidavit that would presumably lay out a detailed factual basis for the search. The department specifically requested the unsealing of the warrant as well as a property receipt listing the items that were seized, along with two unspecified attachments.

Republican fury

The search at Trump’s home sparked fury among his supporters, with some Republican legislators promising to investigate the DoJ, including Garland, if they win power in the upcoming midterm elections.

Others threatened to defund the FBI, accusing the law enforcement agencies involved in the investigation of targeting Trump for political reasons.

But Garland responded to what he called “unfounded attacks” against DoJ and FBI agents and prosecutors.

“I will not stand by silently when their integrity is unfairly attacked. The men and women of the FBI and the Justice Department are dedicated, patriotic public servants … I am honoured to work alongside them,” he said.

Garland’s statement came amid reports of growing threats of violence and even talk of a “civil war” by Trump supporters online after the search.

Republicans had rallied around Trump and come to his defence after the search. “If the Democrats wanted to deal a death blow to Trump, using the FBI as a tool for political gain was not the way to do it,” Congresswoman Lauren Boebert wrote on Twitter on Wednesday.

“Seeing the FBI raid Mar-a-Lago has had the opposite effect. The Republican Party hasn’t been this unified in a long time!”

Trump announced late on Monday on his social media channel that a “large number” of FBI agents had entered Mar-a-Lago in an “unannounced raid”, claiming that they put the estate “under siege” and “broke into” his safe.

The former president described the search as part of a Democrat-led push to prevent him from running for president again in 2024 and called it “political persecution”.

The White House has repeatedly said it did not have prior knowledge of the search and it does not interfere in DoJ-led investigations.

The unprecedented search marks a significant escalation in one of the many investigations Trump is facing in connection with his time as president and as a businessman.

The investigation into the removal of records began earlier this year. (Al Jazeera)

•PHOTO: Trump supporters gathered on Tuesday near his residence at Mar-a-Lago in Palm Beach, Florida [Giorgio Viera/AFP]

Update news