President Donald Trump’s national security adviser, Robert O’Brien, has tested positive for coronavirus, the White House has confirmed.
Mr O’Brien, 54, has been self-isolating and working from home.
The aide has mild symptoms and there was no risk of exposure to Mr Trump or Vice-President Mike Pence, a statement said.
Mr O’Brien is the highest-ranking official in Mr Trump’s administration known to have tested positive.
It is not clear when he and the president last met, but they appeared together two weeks ago on a trip to Miami.
The White House statement read: “He has mild symptoms and has been self-isolating and working from a secure location off site. There is no risk of exposure to the president or the vice-president. The work of the National Security Council continues uninterrupted.”
One source told Bloomberg that Mr O’Brien had been out of his office for a week and that the adviser had contracted the virus after a family event.
Anyone near the president is tested regularly for Covid-19.
A number of people in and around the administration have tested positive, including a military member who works as a White House valet, Mr Pence’s press secretary Katie Miller, and a helicopter squadron Marine.
Mr O’Brien travelled to Paris this month to discuss foreign policy issues with European counterparts, and gave a speech in Arizona in June comparing Chinese President Xi Jinping with Soviet leader Josef Stalin.