Donald Trump's son concerned he's 'acting crazy' after hospital drive-by, late night tweets - report

Donald Trump has been widely criticised for his decision to leave hospital to make a "surprise visit" to supporters while battling COVID-19. But now the incident is worrying a surprising critic - his son.

The US President has been receiving care at the Walter Reed Hospital in Maryland after being diagnosed with COVID-19 on Friday.

On Monday, he thanked supporters gathered outside the facility by completing a drive-by in a car with secret service agents. The only PPE he wore was a face mask.

"I really appreciate all of the fans and supporters outside of the hospital. The fact is, they really love our country and are seeing how we are MAKING IT GREATER THAN EVER BEFORE!" he tweeted.

But the outing was slammed by medical experts and psychologists who called it "political theatre" and said he was putting the agents' lives at risk.

On Monday, Vanity Fair revealed the US President's son Donald Trump Jr was also deeply upset by the drive-by, according to two Republicans briefed on the family's conversations.

"Don Jr thinks Trump is acting crazy," one source told the publication.

He reportedly tried to get his family members Ivanka Trump, Eric Trump and Jared Kushner to help stop the behaviour.

"Don Jr has said he wants to stage an intervention, but Jared and Ivanka keep telling Trump how great he's doing," a source said. 

"Don said, 'I'm not going to be the only one to tell him he's acting crazy'."

The sources also told Vanity Fair the whole family is worried about Trump's Twitter episode late on Monday night where he tweeted multiple times in all-caps.

"STOCK MARKET HIGHS. VOTE!," one tweet said.

Another said: "STRONGEST EVER MILITARY. VOTE!"

"LAW & ORDER. VOTE!"

A source for Vanity Fair said the family are "all worried".

"They've tried to get him to stop tweeting," they said.

The White House has not responded to Vanity Fair's requests for comment.

The US President returned to the White House on Tuesday from the hospital and promised to return to the campaign trail soon ahead of the US election on November 3.

"Feeling really good! Don't be afraid of COVID. Don't let it dominate your life. We have developed, under the Trump Administration, some really great drugs & knowledge. I feel better than I did 20 years ago!" he tweeted. 

The second presidential debate between Trump and Democratic nominee Joe Biden is scheduled for October 16.