White House chief of staff Mark Meadows has tested positive for Covid-19, officials have told US media.
It was not immediately clear how Mr Meadows – who has often appeared at public events without a face mask – was infected.
He is the latest Trump administration official to contract the disease, which has killed some 230,000 Americans.
On Friday, the US set a third straight daily record for new cases, with more than 127,000 infections.
The country’s coronavirus outbreak was a key policy battleground in the run-up to the 3 November election, and contributed to a surge in postal and early in-person voting.
In late October, Mr Meadows said in an interview with CNN that the US was “not going to control the pandemic”, saying that Covid-19 could only be defeated by “mitigation areas” like vaccines and therapeutics.
It was not clear when he first tested positive or whether he had developed symptoms. He has not yet commented.
Mr Meadows travelled with the president on the final days of campaigning and was at an election night party attended by dozens of Trump supporters at the White House.
President Trump and his wife Melania and son Barron all contracted and recovered from Covid-19 as did national security adviser Robert O’Brien, senior advisor Stephen Miller and White House counsellor Hope Hicks.