Who else around the president has tested positive?
4 hours ago
Trump says he is doing well, but next couple of days the 'real test'
Dr Conley did not respond to questions about when and where he believed Mr Trump had been infected. A crowded Rose Garden event last weekend, when the president formally announced his nomination of the conservative Amy Coney Barrett for the Supreme Court, is coming under intense focus.
Aside from the president and the first lady, six other people who attended are now confirmed to have the virus. On Saturday, campaign adviser and former New Jersey Governor Chris Christie became the latest to report a positive result.
Other people to have tested positive around Mr Trump include close aide Hope Hicks - believed to be the first to show symptoms - campaign manager Bill Stepien and former White House counsellor Kellyanne Conway.
Meanwhile, Republican Majority Leader Mitch McConnell said the Senate would postpone its work in full session until 19 October, but that work at the Judiciary Committee - which will examine Judge Barrett's nomination - would continue.
Later on Saturday, the senator said in a tweet he had had a phone call with the president, who sounded "well and says he's feeling good".
Mr Trump remains in charge. Vice-President Mike Pence, to whom under the constitution the president would transfer power temporarily should he become too ill to carry out his duties, tested negative.
The president was last seen in public on Friday evening. Before being flown to the military hospital he waved and gave a thumbs-up to reporters but said nothing before boarding his helicopter.
What about the election campaign?
"I think I'll be back soon and I look forward to finishing up the campaign the way it was started," Mr Trump said in his Twitter message.
The president's campaign team said on Saturday it will move forward "at full speed" until Mr Trump can return to the campaign trail.
It is calling on top "surrogates", including Mr Trump's sons Donald Jr and Eric, and Vice-President Mike Pence to "carry the campaign forward" for the time being.
Dubbed "Operation Maga", a campaign spokesperson told Fox News the first event will be a virtual rally on Monday.
Vice-President Pence, who tested negative on Friday, is scheduled to debate Democratic vice-presidential nominee Kamala Harris on Wednesday.
Democratic challenger Joe Biden has continued his campaign and held a virtual event on Saturday.