US President Donald Trump’s 14-year-old son, Barron, has tested positive for COVID-19 but is exhibiting no symptoms, after both his parents contracted the virus.

“Luckily he is a strong teenager and exhibited no symptoms,” Melania Trump said in a statement posted on the White House web site on Wednesday (local time).

Ms Trump said she and Barron had since tested negative for the virus.

As for her own symptoms, the first lady wrote they were “minimal, though they hit me all at once and it seemed to be a roller coaster of symptoms in the days after.”

“I experienced body aches, a cough and headaches, and felt extremely tired most of the time.”

Ms Trump said she hoped to resume her duties as first lady “as soon as I can”.

“I chose to go a more natural route in terms of medicine, opting more for vitamins and healthy food.”

Mr Trump spent three nights in a military hospital after announcing on October 2 he and Melania had tested positive.

To treat the virus, he received an experimental dual antibody therapy developed by Regeneron Pharmaceuticals and Gilead Sciences antiviral remdesivir, as well as the steroid dexamethasone.

“In one way I was glad the three of us went through this at the same time so we could take care of one another and spend time together,” Melania Trump said.

Top health official Anthony Fauci told CBS Evening News on Wednesday Mr Trump was no longer capable of spreading COVID-19 and could attend a town hall on Thursday without putting others at risk.

Dr Fauci said he and his colleague Clifford Lane at the National Institutes of Health concluded this after reviewing all the tests taken by the president as well as an additional one conducted at an NIH laboratory.

Dr Fauci said last week that it was not known whether Mr Trump was well, because patients can unexpectedly go downhill more than a week after symptoms begin.

The town hall with NBC News is less than three weeks before the election in which Mr Trump is trailing Joe Biden in opinion polls.

Trump campaigns in Iowa

Mr Trump echoed his wife’s update on his youngest son, albeit in more colourful language, while on the election trail in Des Moines, Iowa.

“He had the corona-19, the China virus… it’s got 21 different names.

“To me, ‘corona’ is Italy. China is China and it came from China, so he had the China virus.

“He had it for such a short period of time. I don’t even think he knew he had it.

“Because they’re young … their immune systems are strong and they fight it off.”

Mr Trump continued his attack on his presidential opponent’s credibility, referencing a report in the New York Post that has drawn links between Mr Biden and his son Hunter’s consultancy work for a Ukrainian energy firm Burisma.

“We’ve just learned … that Joe Biden has been blatantly lying about his involvement in his son’s corrupt business dealings.”

“And this is a big smoking gun.”

Mr Trump went on to claim the Hunter Biden may have been paid as much as US$183,000 a month for his work and that the company sought access to his father, who was Vice-President at the time.

“Now we can see clearly that Biden is a corrupt politician who shouldn’t even be allowed to run for the presidency.”

Pointing at the assembled press gallery, Mr Trump then took aim at the “lamestream” media who, he said, are “corrupt. They refused to write the story.”

“They’re trying to protect him.”

Tweet from @realDonaldTrump

Mr Trump also turned his ire on social media giant Twitter, which temporarily locked the account of his press secretary Kayleigh McEnany.

Ms McEnany was temporarily suspended for sharing the report that Mr Trump had referred to in his attack Mr Biden and his son.

Tweet from @PressSec

“Because she’s reporting the truth, they closed down her account.”

The Trump campaign team shared what appears to be a screenshot of a communication Ms McEnany received from Twitter, alerting her that her account “has been locked.”

“We have determined that this account violated the Twitter Rules. Specifically, for: Violating our rules against distribution of hacked material,” the screenshot read.

Tweet from @TrumpWarRoom

Mr Trump elicited an enthusiastic response from his supporters when he spoke of his nomination of Amy Coney Barrett to the Supreme Court.

Democrats believe the Judge Barrett, a staunch conservative, will help to overturn landmark rulings, such as Roe v Wade (1973), which effectively legalised abortion across the US..

A number of “Pro-Life Choices for Trump” banners could be seen at the rally.

“She’s … outsmarting these people with bad intentions. You look at some of these questions being asked.” Mr Trump said.

“It’s so obvious – these are not great chess players.”

As has been customary at his rallies, Mr Trump concluded by urging his supporters to vote.

“Get your friends, get your family, get your neighbours, get your workers and co-workers and get the hell out to vote. Because if I don’t get Iowa – I won’t believe that one.”

-with agencies