US President Donald Trump has been criticised for his “reckless departure” from the Walter Reed National Military Medical Centre, telling his American fan base there was nothing to fear from COVID-19, and removing his mask on the balcony of the White House.

Still infectious with the coronavirus when he returned to the White House on Tuesday morning (Australian time), Mr Trump climbed the stairs at the South Portico, swiftly removed his mask and saluted as he looked over the South Lawn, appearing to be breathing deeply.

CNN reported a source saying “he is done with the hospital”, while a second said the President was concerned being in hospital made him “look weak”.

In a video posted a short time later, Mr Trump defended his conduct and suggested he might be immune from the deadly virus.

“Don’t let it dominate you. Don’t be afraid of it,” he said.

“You’re gonna beat it. We have the best medical equipment, we have the best medicines, all developed recently. And you’re gonna beat it. I went, I didn’t feel so good, and two days ago, I could have left two days ago, two days ago I felt great, like better than I have in a long time.

“I said just recently, better than 20 years ago. Don’t let it dominate. Don’t let it take over your lives. Don’t let that happen. We have the greatest country in the world.”

“We’re going back to work. We’re going to be out front. As your leader I had to do that. I knew there was danger to it, but I had to do it. I stood out front. I led. Nobody that’s a leader would not do what I did.

“Maybe I’m immune, I don’t know. But don’t let it dominate your lives. Get out there, be careful, we have the best medicines in the world. And it all happened very shortly, and they’re all getting approved, and the vaccines are coming momentarily.”

Later, the President’s niece, Mary Trump, who wrote a tell-all memoir Too Much and Never Enough: How My Family Created the World’s Most Dangerous Man, told CNN her uncle subscribed to “the doctrine of the power of positive thinking”.

“It makes perfect sense to me that Donald, no matter how sick he may or may not be, would pull this kind of stunt,” she said.

Tweet from @JoeBiden

Masks matter: Biden

In a town hall on MSNBC on Monday, Democratic nominee Joe Biden said he hoped Mr Trump “would communicate the right lesson to the American people. Masks matter.”

“There’s a lot to be concerned about – 210,000 people have died,” Mr Biden continued.

“I hope no one walks away with a message thinking that it is not a problem. It’s a serious problem. It’s an international pandemic.”

He also argued it should be seen as a patriotic duty to wear a mask.

Asked if Mr Trump bore some responsibility for contracting the virus, Mr Biden said, “Look, anybody who contracts the virus by essentially saying masks don’t matter, social distancing doesn’t matter, I think is responsible for what happens to them.”

Mr Trump on the White House balcony shortly after his return from hospital.

Leaving the military hospital just outside Washington about 6.30pm on Monday (local time), Trump gave a thumbs up but did not answer a shouted question from a reporter: “Do you think you might be a super-spreader, Mr President?”

He was driven to his official helicopter, Marine One, which then ferried him to the South Lawn of White House.

Mr Trump had tweeted earlier in the day that he was ready to leave hospital.

“Feeling really good!” he said. “Don’t be afraid of COVID. Don’t let it dominate your life. We have developed, under the Trump administration, some really great drugs and knowledge. I feel better than I did 20 years ago!”

Earlier, Mr Trump’s physician Sean Conley said that the President might “not be entirely out of the woods yet”, but that he was cleared to return to the White House.

Dr Conley declined to say when Mr Trump had last tested negative for the virus, or to share results of his lung scans, citing privacy laws.

Dozens more within Trump circle test positive

Mr Trump’s return to the White House came as a growing circle of presidential advisers tested positive to the virus.

On Monday morning, Kayleigh McEnany, the White House press secretary, confirmed she had COVID-19, as did two of her aides.

-with agencies