US President Donald Trump staged a dramatic return to the White House after leaving the military hospital where he has been receiving an unprecedented level of care for Covid-19.

He immediately ignited a new controversy by declaring that, despite his illness, the nation should not fear the virus that has killed more than 210,000 Americans - and then he entered the White House without a protective mask.

Mr Trump's message alarmed infectious disease experts and suggested the president's own illness had not caused him to rethink his often-cavalier attitude toward the disease, which has also infected the first lady and several White House aides, including new cases revealed on Monday.

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Landing at the White House on Marine One, Mr Trump gingerly climbed the South Portico steps, removed his mask and declared: "I feel good."

He also hailed his actions saying: "I stood out front. I led. Nobody that's a leader would not do what I did. I know there's a risk, there's a danger, but that's OK.

"And now I am better, maybe I'm immune. I don't know"

He gave a double thumbs-up to the departing helicopter from the portico terrace, where aides had arranged American flags for the sunset occasion and he entered the White House, where aides were visible milling about the Blue Room, without wearing a face covering.

The president left Walter Reed National Military Medical Centre, where his doctor Navy Commander Sean Conley, said earlier on Monday that the president remains contagious and would not be fully "out of the woods" for another week but that Mr Trump had met or exceeded standards for discharge from the hospital.

He is expected to continue his recovery at the White House, where the reach of the outbreak that has infected the highest levels of the US government is still being uncovered.

Mr Trump indicated he will not be kept from campaigning for long, tweeting before leaving the hospital: "Will be back on the Campaign Trail soon!!!"

Mr Trump made a point of sounding confident, tweeting: "I will be leaving the great Walter Reed Medical Center today at 6:30 P.M. Feeling really good! Don't be afraid of Covid. Don't let it dominate your life. ... I feel better than I did 20 years ago!"

His nonchalant message about not fearing the virus comes as his own administration has encouraged Americans to be very careful and take precautions to avoid contracting and spreading the disease as cases continue to spike across the country.

"We have to be realistic in this: Covid is a complete threat to the American population," Dr David Nace of the University of Pittsburgh Medical Centre, said of Mr Trump's comments.

Dr Sadiya Khan of Northwestern University Feinberg School of Medicine said: "It's an unconscionable message.

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"I would go so far as to say that it may precipitate or worsen spread."
There was political pushback to Mr Trump's attitude toward the virus as well.
Republican Senator John Cornyn told the Houston Chronicle editorial board that Trump had "let his guard down"" in his effort to show that the country was moving beyond the virus and had created "confusion" about how to stay safe.

According to the Centres for Disease Control and Prevention, those with mild to moderate symptoms of Covid-19 can be contagious for as many - and should isolate for at least - 10 days.

Mr Trump's discharge raised new questions about how the administration was going to protect other officials from a disease that remains rampant in the president's body.

Press secretary Kayleigh McEnany announced she had tested positive for the virus on Monday morning and was entering quarantine.