President Donald Trump says his eldest son, Donald Trump Jr. is doing “very well” in quarantine after becoming infected with coronavirus.

“My son Donald is doing very well. Thank you!” the president tweeted, the day after the disclosure that the 42-year-old Trump scion had become one of the nearly 12 million Americans infected by the virus.

More than 250,000 Americans have lost their lives to the virus, the highest death toll of any country.

Trump Jr. learned of his positive test result earlier this week, has had no symptoms and was following all medically recommended guidelines for treating the illness, a spokesperson said.

Mr Trump Jr’s girlfriend, Kimberly Guilfoyle, tested positive for the virus over the summer as the duo campaigned for Mr Trump throughout the country.

On Friday (local time), Rudy Giuliani’s son Andrew Giuliani, another White House aide, announced he had tested positive.

My son Donald is doing very well. Thank you!

— Donald J. Trump (@realDonaldTrump) November 21, 2020

Mr Trump Jr is the latest member of the President’s family and inner circle to become infected with the virus.

The President, the first lady and their son Barron have recovered from the virus.

Mr Trump spent three days in a military hospital where he was treated with experimental drugs; the first lady weathered her illness at the White House.

Mr Trump’s chief of staff Mark Meadows and a number of other top aides both in his campaign and in the White House have also tested positive in recent months.

The news comes as the coronavirus pandemic surges in the US, with daily new cases regularly topping 150,000 since last week. More than 250,000 Americans have died from the virus.

President-elect Joe Biden made the President’s response to the virus a top issue in the recently concluded race for the White House, although Mr Trump has yet to acknowledge the outcome.

-with AAP