At a news conference Monday afternoon, the president's physician declined to comment on Trump telling Americans not to be afraid. "I’m not going to get into what the president says," Dr. Sean Conley said.
Trump has for months has played down the threat of the pandemic, mocked mask-wearing, flouted public health guidelines and expressed little empathy for the nearly 210,000 Americans who have died.
Criticized for mishandling his response, he and his campaign now are casting him as someone strong and uniquely qualified to lead the fight.
"I learned a lot about COVID," Trump said in a video he tweeted Sunday afternoon. "I learned it by really going to school. This is the real school. This isn’t the, ‘Let’s-read-the-book school.’ And I get it. And I understand it. And it’s a very interesting thing, and I’m going to be letting you know about it."
"I feel better than I did 20 years ago!" he tweeted Monday afternoon.
A spokeswoman for his campaign on Monday criticized the Democratic presidential nominee, former Vice President Joe Biden, for having not contracted the virus himself.
"He has experience now fighting the coronavirus as an individual," Erin Perrine, director of press communications for Trump's campaign, said in an interview with Fox News Monday morning. "Those first-hand experiences Joe Biden, he doesn't have those."
In stark contrast with Trump, Biden has for months practiced strict coronavirus protocols, severely limiting the sizes of his events and frequently wearing a face covering. He has repeatedly said he would trust public health officials -- unlike Trump, who has disagreed with them in public, politicized mask-wearing and made false and misleading claims about treatments and vaccines.
Biden's campaign has followed strict social distancing in order to keep the candidate safe and project an image of responsibility in contrast, they say, with Trump's mishandling of the pandemic.
The president has been undergoing medical treatment at the hospital at Walter Reed, in Bethesda, Maryland, since Friday. He traveled by helicopter to the facility.
Under the care of a number of top physicians, he has received supplemental oxygen and treatment with the steroid dexamethasone, the antiviral medication remdesivir, and a monoclonal antibody cocktail.
Even as aides said the president wanted to return to the White House, more officials there tested positive over the past few days.
White House press secretary Kayleigh McEnany said she had tested positive Monday morning. Chad Gilmartin, a principal assistant press secretary who is also McEnany's husband's cousin, also tested positive over the weekend, sources told ABC News.
A third staffer in the White House press office, assistant press secretary Karoline Leavitt, also received a positive test for the virus, a source with direct knowledge told ABC News.
Trump's wife, first lady Melania Trump, is also sick with the virus, according to the White House. She has remained in the White House since testing positive Thursday, according to the White House.
At least 17 people who work at or have visited the White House -- ranging from top staffers and outside advisers to journalists and Republican senators -- have tested positive for COVID-19.
Despite that -- and despite Trump's condition -- Conley, the president's doctor, said the president's return would be "safe."
"We’ve worked with our infectious disease experts to make some recommendations for how to keep everything safe, down at the White House, for the president and those around him," Conley told reporters Monday afternoon.
He added that Trump "is returning to a facility, the White House Medical Unit, that is staffed 24/7, top-notch physicians, nurses, [physician assistants], logisticians, and the unit here -- the team here behind me is going to continue to support us in that nature."
The president’s personal attorney and close confidante Rudy Giuliani said he spoke to the president by phone Sunday night and said on ABC's “Good Morning America” Monday morning that the president was so eager to be discharged from the hospital that he was worried the president would try to "escape" overnight.
"He's feeling great. I was worried when I woke up this morning that he escaped during the night. He wants to get out. He sounds perfect. I just cautioned him to listen to his doctors. I said I hope that's not your decision, it's the doctors. He said no no these guys are great. I'll do what they tell me. I think whatever happens will be the decision of his doctors," Giuliani said.
The president, eager to project an image of health, made an last-minute trip out of his hospital suite Sunday evening to do a drive-by of supporters who gathered along the road outside the hospital in a show of support for the president.
The masked president, who wore a cloth face covering, drove by supporters and waved through the window of the back seat of a sports utility vehicle, driven by a Secret Service officer and another agent seated in the passenger side seat. Both agents appear to have worn full protective gear, including masks, face shields, and coverings over the clothes.
Despite the protection worn by the other agents, Dr. James Phillips, an attending physician at Walter Reed criticized the trip as a “stunt” with a “very high risk of transmission” posed to the officers who were in the car with the president.
“As a physician, we look at the decisions we make as risks versus benefits. I don't know what the benefits of this political stunt were, but I do know what the risks were. And my concern is that perhaps the Secret Service agents that were inside don't know the risks they were up against there and what the real threats were,” Phillips said.
Meadows brushed off the criticism of the president’s non-essential drive-by outside Walter Reed, saying some are “trying to just make a big deal” of it, and drew a false comparison to the other essential interactions the Secret Service have had with him in transporting him to Walter Reed and in protecting him there.
“How do we think that we got here? We came here in Marine One, the Secret Service agent that is with him has been with him, he's been with him in cars and yet we took additional precautions with PPE and others to make sure that they were protected,” Meadows said.
Also on Monday, CNN released an audio recording in which Trump told the veteran journalist Bob Woodward in March that he did not have "a lot of time" to meet with Dr. Anthony Fauci, the top infectious disease expert in the federal government.
"There's not a lot of time for that, Bob," he said. "This is a busy White House. This is a busy White House. We've got a lot of things happening. And then this came up."
ABC News' Terrance Smith, Anne Flaherty, Katherine Faulders and John Santucci contributed to this report.