President Trump briefly left Walter Reed Medical Center on Sunday evening to wave to his supporters. The motorcade left around 5:20 p.m. and looped around for a few minutes before he returned.
In a video Mr. Trump posted to Twitter shortly before departing, he said he wanted to "pay a little surprise to some of the great patriots we have out on the street. They've been out there a long time, they have Trump flags and they love our country."
Mr. Trump also said he "learned a lot about COVID" while in the hospital.
"I learned it by really going to school," he said. "This is the real school, this isn't the 'let's read the books school,' and I get it, I understand it. And it's a very interesting thing and I'm going to be letting you know about it."