In the days since the F.B.I. searched Mar-a-Lago, former President Donald J. Trump’s private club and home in Florida, the White House has made a point of staying quiet.
President Biden was not given advance notice of the search on Monday, Karine Jean-Pierre, the White House press secretary, said this week. And a White House official said Mr. Biden was not given a heads-up that Attorney General Merrick B. Garland would speak to reporters on Thursday, when he announced that the Justice Department was moving to unseal the search warrant.
The White House’s approach is part of a concerted effort to make sure the law enforcement operation is not seen as partisan.
Mr. Biden promised during his presidential campaign to restore the independence of the Justice Department, which Mr. Trump tried to weaponize for political gain. Mr. Biden’s team is also aware that opining on the F.B.I. search would most likely fuel accusations by Mr. Trump’s allies that the president was using the Justice Department to weaken a probable opponent in the 2024 presidential election.
“President Biden has been very clear from before he was elected president and throughout his time in office that the Justice Department conducts its investigations independently,” Ms. Jean-Pierre said this week. “He believes in the rule of law.”
Still, top Republicans and prominent conservatives have tried to assail federal law enforcement officials as biased against the former president. A number of House Republicans, including Representative Kevin McCarthy of California, the minority leader, raced to portray the search as politically motivated. Mr. Trump has also said the search is a part of a “witch hunt.”
But in recent days, Republicans in the Senate, including Senator Mitch McConnell of Kentucky, the minority leader, have softened their tone while still pressing for more information about the evidence that led the authorities to seek a warrant, which was approved by a federal judge.
The investigation centers on whether Mr. Trump improperly took sensitive materials with him from the White House and then failed to return all of them — including classified documents — when the National Archives and the Justice Department demanded that he do so.
Mr. Biden and Mr. Garland have faced growing pressure since taking office to advance another investigation: the one into the Capitol attack on Jan. 6, 2021.
But the White House knows any comment from Mr. Biden would fuel accusations that the Justice Department investigation is politically motivated. In October, after the president said that those who defied subpoenas to appear in front of the Jan. 6 House committee should be prosecuted, he admitted he was wrong to have made the statement.
“I should have chosen my words more wisely,” he said.