Walter Reed doctor slams Donald Trump's decision to leave hospital 'to surprise patriots' while still positive for COVID-19

President Donald Trump's last-minute "surprise visit" outside Walter Reed military hospital on Monday has been described as "irresponsible" and "completely unnecessary".

The US President was taken to the hospital after being diagnosed with COVID-19 on Friday but decided to leave the hospital and drive by his supporters in an SUV.

"This is insanity," Walter Reed physician Dr James Phillips tweeted.

"Every single person in the vehicle during that completely unnecessary Presidential 'drive-by' just now has to be quarantined for 14 days. They might get sick. They might die. For political theatre. Commanded by Trump to put their lives at risk for theatre."

Trump announced earlier on Monday tells the public his plan to leave the hospital to "pay a little surprise to some of the patriots".

"This is an incredible hospital, Walter Reed. The work they do is just absolutely amazing and I want to thank them all, the nurses, the doctors, everybody here," Trump said in a video posted on Facebook.

"I also think we're going to pay a little surprise to some of the patriots that we have out on the street and they've been out there for a long time."

A video published by White House correspondent Phillip Crowther shows Trump waving to his fans as they were all screaming in support.

"That Presidential SUV is not only bulletproof but hermetically sealed against chemical attack. The risk of COVID-19 transmission inside is as high as it gets outside of medical procedures," Dr Phillips said.

"The irresponsibility is astounding."

After being diagnosed, Trump went from having 'mild symptoms' of COVID-19 on Friday to being taken to hospital with 'trouble breathing' on Saturday.

"He risks the health of everybody in the car. He has not learned a thing," a Twitter user commented.

"I wish EVERYONE who tested positive for COVID-19 was well enough in 4 days to go parading around waving at people. Unfortunately, 209,000+ people have died and the number is rising daily. Maybe instead, he should be "working" on everyone getting quality healthcare. Just a thought," another said.