Mueller has indicted more than 30 individuals, including 25 Russians, and three companies
Donald Trump said Monday he does not plan to fire the deputy attorney general in charge of a probe into alleged collusion between the president and the Kremlin.
The official, Rod Rosenstein, had appeared close to being sacked following US media reports - which he denied - that he discussed secretly recording Trump and using the 25th constitutional amendment for removing presidents found to be unfit for office.
"I'm not making any changes," Trump told journalists at the White House when asked whether he plans to fire Rosenstein.
The pair spoke at length during a flight Monday for a visit lasting just a few hours in Florida, according to the White House.
"The president and Deputy Attorney General Rod Rosenstein met for about 45 minutes aboard Air Force One," spokesman Hogan Gidley said.
"They discussed various topics," including border controls, violent crime in Chicago and "general" Justice Department business, the spokesman added.
"We just had a very nice talk. We actually get along. Really good," Trump said on return to the White House from Florida.
The president used the occasion to again insist that "there's been no collusion, folks, no collusion" with Russia.
The Republican real estate billionaire is infuriated by what he calls Special Counsel Robert Mueller's "witch hunt" into whether Moscow conspired with his campaign in the shock 2016 election win.
Mueller has indicted more than 30 individuals, including 25 Russians, and three companies.
Five have negotiated guilty pleas on reduced charges, including Trump's former national security advisor Michael Flynn, former deputy campaign chair Richard Gates, and former foreign policy advisor George Papadopoulos.
Rosenstein, who oversees Mueller, has so far been steadfast in trying to protect the investigation as it digs ever deeper into Trump's inner circle.
So Rosenstein's departure - possibly putting someone more pliable in his place - would set off alarm bells over the future independence of a probe that could rock the entire presidency.