WASHINGTON — The Justice Department said Monday that prosecutors were looking into whether a special counsel should be appointed to investigate the president’s political rivals, including Hillary Clinton.
The department said the prosecutors would examine allegations that donations to the Clinton Foundation were tied to a 2010 decision by the Obama administration to approve the sale of uranium to a Russian nuclear agency.
If prosecutors do appoint a special counsel, it is a move that could raise questions about the independence of federal investigations under President Trump.
Since Watergate, the Justice Department has largely operated independently of political influence on cases related to the president’s opponents. But the disclosure appeared to be a direct response to signals that Mr. Trump sent to his beleaguered attorney general, Jeff Sessions, 10 days ago in the news media. Mr. Trump said that he was disappointed in Mr. Sessions and said that longstanding unproven allegations about the Clintons and the Obama administration should be investigated.
Mr. Trump’s statement galvanized conservative news outlets — like Fox News and Breitbart — which have since beaten the drum for a special prosecutor to be appointed.
People close to the White House believe Mr. Sessions — who offered to resign in May — can forestall the president from firing him by appointing a special counsel to investigate the uranium deal. Mr. Sessions is scheduled to testify Tuesday before the House Judiciary Committee, where he is expected to be questioned sharply by both Republicans and Democrats.
Although Mr. Sessions has recused himself from all matters relating to the election, including the inquiry into Mr. Trump’s campaign, he and the deputy attorney general, Rod J. Rosenstein, will oversee the prosecutors’ decision to appoint the special counsel, according to a letter the Justice Department sent to the House Judiciary Committee on Monday.
The prosecutors, according to Stephen E. Boyd, an assistant attorney general, who wrote the letter, “will make recommendations as to whether any matters not currently under investigation should be opened, whether any matters currently under investigation require further resources, or whether any matters merit a special counsel.”
Republicans have long tried to link Mrs. Clinton to the uranium deal, which was revealed in the run-up to her 2016 presidential campaign. The deal was approved by the Committee on Foreign Investment in the United States when she was secretary of state under President Barack Obama and had a voting seat on the panel. Conservative news outlets have repeatedly pushed unproven allegations that Mrs. Clinton was part of a quid pro quo in which the Clinton Foundation received large donations in exchange for support of the deal.
As the special counsel’s investigation into Mr. Trump and his associates has intensified in recent weeks, Mr. Trump has asked allies and advisers why the special counsel, Robert S. Mueller III, is not investigating the Uranium One case, according to a person familiar with the president’s discussions on the matter.
The allies and advisers have told Mr. Trump that Mr. Mueller’s purview is only to look into Russian interference in the 2016 election, the person said. In response, Mr. Trump has said that the uranium deal should be investigated the same way because it relates to Russia.
Before leaving for a 12-day trip to Asia this month, Mr. Trump publicly vented about how the Justice Department had operated under Mr. Sessions. Mr. Sessions had been one of the few prominent national politicians to embrace him during the Republican presidential primary race, but their relationship deteriorated after Mr. Sessions recused himself from all matters related to the 2016 election and then got worse after Mr. Mueller was appointed.
“I’m really not involved with the Justice Department,” Mr. Trump told reporters. “I’d like to let it run itself.”
“But, honestly, they should be looking at the Democrats,” Mr. Trump said.
He added: “And a lot of people are disappointed in the Justice Department, including me.”
Mr. Trump has been repeatedly criticized for trying to intervene in the Justice Department’s investigations since he took office. In May, it was revealed that Mr. Trump had asked James B. Comey, then the F.B.I. director, to end the investigation into Mr. Trump’s former national security adviser — a disclosure that led to the appointment of Mr. Mueller. Mr. Trump has repeatedly criticized Mr. Mueller’s investigation — which has intensified in recent weeks as three Trump campaign members were charged — as a witch hunt.
Commentators in the conservative news media ecosystem where Mr. Trump often pulls ideas from have been calling for an investigation into the Uranium One deal for weeks. In discussions with aides, Mr. Trump has cited those reports as examples for why a special counsel should be appointed.
One commentator in particular, the Fox News host Jeanine Pirro — who is a friend of Mr. Trump and whose show he rarely misses — has aggressively denounced Mr. Sessions as weak for not probing the uranium deal. In addition to making scathing critiques on her show, Ms. Pirro — who had interviewed to be the deputy attorney general, according to three transition officials — recently met with the president to excoriate the attorney general.
In an Oval Office meeting on Nov. 1, Ms. Pirro raised said that a special counsel needed to be appointed, according to two people briefed on the discussion. Through a Fox News spokeswoman, Jeanine Pirro said, “Everything I said to President Trump is exactly what I’ve vocalized on my show, ‘Justice with Jeanine.’”