ALEX EDELMAN/AFP via Getty Images

President Donald Trump briefly left Walter Reed National Military Medical Center to wave at his supporters on Sunday, which was day 3 of his coronavirus hospitalization.

Possibly concerned about optics and taking publicity matters into his own hands, Trump, who was wearing a black face mask, was driven by his presidential motorcade in front of the D.C. hospital. Waving his bare hand from one of the black SUVs, Trump, 74, greeted the crowds of people who were waving "Make America Great Again" flags and posters.

Minutes prior to Sunday's unannounced car ride, Trump tweeted another video from the hospital. "We're getting great reports from the doctors. This is an incredible hospital, Walter Reed. The work they do is absolutely amazing. I want to thank them all, the nurses, doctors. I've also got to meet some of the soldiers and what a group," he began.

"I also think we're going to pay a little surprise to some of the great patriots we have out on the street and they've been out there for a long time. They have Trump flags and they love our country, so I'm not telling anybody but you, but I'm about to make a little surprise visit," he said.

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Speaking about his coronavirus diagnosis, which he publicly revealed early Friday morning, the president, who was given three drugs -- dexamethasone, Regeneron's antibody treatment and remdesivir -- during his stay so far, said: "It's been a very interesting journey."

"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-book-school. And I get it," Trump said. "I understand it. It's a very interesting thing, I'll be letting you know about it."

After his short drive, Trump returned to his presidential suite. "President Trump took a short, last-minute motorcade ride to wave to his supporters outside and has now returned to the Presidential Suite inside Walter Reed," said Judd Deere, the president's deputy assistant.

Also after Trump's drive-by greeting, Press Secretary Kayleigh McEnany told reporters that the president's "first positive test" was after attending a fundraiser at his golf club in Bedminster, New Jersey, on Thursday.

RELATED: Trump's Doctor Admits to Omitting Details of President's Condition: 'Was Trying to Reflect Upbeat Attitude'

Earlier in the day, Trump's team of doctors, led by physician Sean Conley, told reporters during a press conference that the president could potentially be discharged from the hospital and back in the White House tomorrow if he continues to improve.

"He has been up and around. Our plan today is to have him eat and drink, be up out of bed," said Dr. Brian Garibaldi. "[If] he continues to look and feel as well as he does today, our hope is to plan for discharge as early as tomorrow to the White House, where he can continue his treatment course."

Dr. Sean Dooley said the president "continues to improve" and has been without a fever since Friday morning, adding that Trump is "not complaining of shortness of breath" and is walking around his medical quarters in the hospital "without limitation or disability."

Shutterstock Donald Trump

In addition, Conley, who confirmed the president had received supplemental oxygen while at the White House on Friday morning, was asked why the medical staff had been cagey about the use of oxygen in previous statements.

"I didn't want to give any information that might steer the course of illness in another direction and in doing so it came off that we were trying to hide something, which wasn't necessarily true," he said, sharing that he was "trying to reflect the upbeat attitude that the team, the president, his course of illness has had."

Also addressing the mixed messages given by him and chief of staff Mark Meadows, Conley said Meadow's Saturday statement about the president's "very concerning" vitals was "misconstrued" and that Meadows was referring to Trump's report before he was admitted to the hospital.

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