Trump leaves hospital briefly to greet supporters outside

US President Donald Trump briefly left the hospital on Sunday in his car to wave to supporters gathered outside. 

The president's visit came shortly after he promised his supporters “a surprise” in a video posted on social media. 

“It’s been a very interesting journey," Trump said in the video. "I learned a lot about Covid. I learned it by really going to school. This is the real school. This isn’t the let’s read the books school. And I get it, and I understand it. And it’s a very interesting thing.”

Earlier, his medical team said that has "continued to improve" as he is treated for Covid-19, revealing he could be discharged as early as Monday.

His medical team said on Sunday that his oxygen levels had dropped twice briefly in recent days and he is being treated with steroids, but they gave an upbeat assessment of the 74-year-old president's health and outlook.

"Since we spoke last, the president has continued to improve. As with any illness, there are frequent ups and downs over the course," said Trump's physician Sean Conley.

Conley said the president was flown to Walter Reed military hospital on Friday after a "rapid progression" of his illness, with his oxygen levels dropping worryingly low.

He received supplementary oxygen at the White House before being admitted. 

Brian Garibaldi, another of Trump's doctors, said the president had been "up and around" and was feeling well. 

"Our plan for today is to have him eat and drink, be up out of bed as much as possible, to be mobile," Garibaldi said.

"And, if he continues to look and feel as well as he does today, our hope is that we can plan a discharge as early as tomorrow to the White House, where he can continue his treatment course."

He said Trump received a second dose of the experimental drug remdesivir along with the first dose of dexamethasone a day ago and is not showing any side effects "that we can tell."

READ MORE: Doctors: Covid-hit Trump doing 'very well' in hospital

Conflicting reports

White House Chief of Staff Mark Meadows had said on Saturday that Trump's health had left the doctors "very concerned" but that he had improved and there was never a risk he would have to hand over power.

Meadows' comments to Fox News capped a day of back-and-forth in which conflicting reports about the president's health created widespread confusion.

Late Saturday, Conley warned that Trump was "not yet out of the woods," but that the medical team was "cautiously optimistic."

The president posted a video to Twitter late on Saturday appearing relaxed in an open-collar shirt and blue suit jacket, telling viewers he would be "back soon"  – but acknowledging that the crucial coming days would be "the real test."

READ MORE: Trump joins growing list of world leaders testing positive for coronavirus

O'Brien: Trump feels very well

Earlier on Sunday, White House National Security Adviser Robert O'Brien said Trump feels very well and wants to get back to work at the White House but will remain hospitalised.

"I spoke with the Chief of Staff (Mark Meadows) this morning and the good news is the president feels very well and he actually wants to get back home to the White House and get back to work, but I think he's going to stay at Walter Reed for at least another period of time," O'Brien told CBS's "Face the Nation."

O'Brien, who himself had coronavirus over the summer, said the seventh and eighth days "are the critical days so I think the doctors want to make sure that they're there for the president."

WH staff, top Republicans test positive 

A growing number of White House staff and senior Republicans have tested positive for Covid-19 since Trump revealed he had contracted the respiratory disease.

The infections have roiled the presidential campaign, now in its final month, rattled financial markets and slowed the work of Congress, with the Senate vowing to delay any votes now that three members of the Republican majority have tested positive.

Several people who met with the president last week said they had since tested negative, but it can take days for someone who has been exposed to the virus to develop symptoms or to test positive.

Below is a list of people close to Trump who have tested positive for coronavirus in recent days:

Hope Hicks 

Hope Hicks, a close adviser to the president who often travelled with him on the Air Force One and Marine One presidential aircraft, tested positive for the disease caused by the novel coronavirus on Thursday. The disclosure of her infection, first reported by Bloomberg, set off a wave of news.

Melania Trump

Donald Trump, who had a busy week of campaigning starting with the September 26 introduction of his Supreme Court nominee Amy Coney Barrett at a packed White House ceremony, said on Friday that he and his wife, Melania, had tested positive.

Ronna McDaniel 

Republican National Committee Chair Ronna McDaniel, who has had frequent contact with Trump, said on Friday she tested positive for the virus and was quarantined at home in Michigan.

Senator Ron Johnson 

Ron Johnson, who heads the Senate Homeland Security and Governmental Affairs Committee, tested positive for Covid-19 on Friday, a spokesperson said on Saturday.

Senator Thom Tillis 

Senator Thom Tillis tested positive for the coronavirus, he said in a statement on Friday. A member of the Senate Judiciary Committee, Tillis' positive test results comes after he attended a September 26 Oval Office meeting with Barrett, who Republicans are seeking to steer onto the Supreme Court.

Senator Mike Lee  

Mike Lee, another senator on the Judiciary Committee, also said he tested positive on Friday. He was present at the Oval Office meeting on September 26.

Bill Stepien 

Trump's campaign manager, Bill Stepien, also tested positive for Cocid-19 on Friday and will work from home, according to a senior campaign official.

Governor Chris Christie 

Former New Jersey Governor Chris Christie said on Saturday that he was checking himself into a hospital as a precautionary measure after testing positive for coronavirus.

Kellyanne Conway  

Kellyanne Conway, a former counselor to Trump, said in a post on Twitter that she had tested positive for Covid-19 on Friday. She attended the September 26 Rose Garden ceremony for Barrett.

Notre Dame President John Jenkins  

University of Notre Dame President John Jenkins, who also attended the White House ceremony, said on Friday that he had tested positive.

Nicholas Luna 

Assistant to Trump Nicholas Luna, a "body man" who accompanies the president day and night, has tested positive, CNN reported, citing an unnamed White House official. Administration officials declined to comment on the report. 

READ MORE: Too little, too late? Trump embraces masks in about-face