The White House has said Donald Trump "has no intention" of sacking the special counsel investigating Russian meddling in the 2016 presidential election.
Spokeswoman Sarah Huckabee Sanders told reporters aboard Air Force One that "while the president has the right to" fire Robert Mueller, "he has no intention to do so".
President Trump has railed against the Russia investigation, describing it as a "witch hunt".
Under Department of Justice rules, it is actually up to the deputy attorney general to make that call, though the president could bypass that protocol.
Some of Mr Trump's allies have begun questioning Mr Mueller's credibility as the investigation intensifies.
Ms Sanders also said the president was pleased with attorney general Jeff Sessions' evidence to Congress on Tuesday.
She said Mr Trump was not able to watch much of Mr Sessions' testimony, but he thought Mr Sessions "did a very good job" and was especially "strong" on denying any collusion between Mr Trump's campaign and Russia.
Mr Sessions vigorously denied having an undisclosed meeting with Russia's ambassador to the US.
He also declared it a "detestable and appalling lie" to suggest he was aware of or took part in any collusion between Russia and the election campaign that sent Mr Trump to the White House.
Investigations are currently under way into Russian meddling in the 2016 election.