Donald Trump Jr, the president’s eldest child, has tested positive for coronavirus.
A spokesman said: “He’s been completely asymptomatic so far and is following all medically recommended COVID-19 guidelines.”
The 42-year-old is the latest member of the president’s family to become infected with a virus that has killed more than 250,000 Americans and infected nearly 12 million others.
President-elect Joe Biden made the president’s response to the virus a top issue in the recently concluded race for the White House, though Mr Trump has yet to acknowledge the outcome.
President Trump, first lady Melania Trump and their son Barron have all recovered from their coronavirus infections in October.
The president spent three days in a military hospital where he was treated with experimental drugs; the first lady weathered her illness at the White House.
Donald Trump Jr’s girlfriend, Kimberly Guilfoyle, tested positive for the coronavirus in July.
Andrew Giuliani, the son of the president’s personal lawyer Rudy Giuliani, also said he tested positive for COVID-19 on Friday.