US President Donald Trump has briefly left hospital for a motorcade procession past supporters gathered outside, appearing in good health.

The unscheduled appearance attracted criticism, with the President accused of sowing further confusion about his condition.

The President just drove past his festival of fans outside the Walter Reed Medical Centre – he was wearing a mask and waving wildly out the window! He gave us a thumbs up.@9NewsAUS @TheTodayShow

— Alexis Daish (@LexiDaish) October 4, 2020

Former US government official Kim Hoggard told Deborah Knight the drive-by was “quite surprising”, and said it was likely approved by Mr Trump’s doctors as a “psychological boost”.

“But by doing it, I think he sends the wrong message to Americans and to the world about the seriousness of the pandemic.”

Ms Hoggard was critical of confusing communication from the White House, and said there should have been a plan in place for this scenario.

“When I worked in the Reagan administration, when the President was shot, there was a lot of confusion … but we were constantly trying to get information to the media.

“The President was felled by a bullet from an assassination attempt: this President has been felled by a virus that we’ve known about for 10 months.”

Click PLAY below to hear the full interview

Image: Nine News