The president had already tested positive Thursday when he appeared on Fox News.
President Donald Trump's condition is continuing to improve as he fights a coronavirus infection, doctors say, and he may be able to leave Walter Reed Medical Center as early as Monday -- even as details emerge that the president allegedly initially tested positive for COVID-19 earlier than he acknowledged.
Doctors also reported that Trump, over the course of exhibiting coronavirus symptoms, had earlier experienced two episodes of "transient drops" in his oxygen saturation.
Yet the president was feeling well enough Sunday evening to briefly leave Walter Reed for a surprise drive-by, waving to supporters outside the hospital.
Meanwhile, numerous questions remain about how many people at the highest levels of government had been exposed to the virus after a week of events involving the president where social distancing and mask-wearing were lax in the White House and elsewhere.
A press conference will be held around 11:30 a.m. outside Walter Reed Medical Center, the White House told the press pool, as Trump continues undergoing treatment for the coronavirus.
The briefing is expected to be from Dr. Conley and the president’s medical team.
As President Donald Trump remains hospitalized at Walter Reed National Military Medical Center after contracting COVID-19 this week, nearly 3 out of every 4 Americans doubt that he took seriously the threat posed to his well-being nor the steps necessary to avoid contracting the virus, according to a new ABC News/Ipsos poll released Sunday.
In two separate questions, an identical 72% said that Trump did not take the "risk of contracting the virus seriously enough," nor "the appropriate precautions when it came to his personal health." The poll was conducted by Ipsos in partnership with ABC News using Ipsos' Knowledge Panel on Friday and Saturday, following Trump's positive test early Friday morning.
In each of the two questions, over 2 in 5 (43%) Republicans hold the negative sentiments about Trump's mindset and preventative actions regarding the coronavirus, compared to 95% and 94% of Democrats, respectively.
-ABC News' Adam Kelsey
Trump campaign senior adviser Jason Miller told ABC News chief anchor George Stephanopoulos on ABC's "This Week" on Sunday that White House senior adviser Stephen Miller, who was part of Trump's debate preparations last Monday, has tested negative for the coronavirus.
Jason Miller has also tested negative for COVID-19.
ABC News has confirmed that five out of nine known participants in Trump's debate preparations have tested positive, including campaign manager Bill Stepien, former senior adviser Kellyanne Conway, former counselor Hope Hicks and former New Jersey governor and ABC News contributor Chris Christie.
Rudy Giuliani said on Fox News on Sunday morning that he held about a 35 to 40 minute phone conversation with Trump on Saturday where they went over his health and the campaign.
"I had to kind of get him off the phone so he went back and rested," Guiliani said in the interview.
Giuliani says the president told him that he "felt pretty bad the first day", but, as of 3 p.m. on Saturday that he "felt perfectly fine", had no fever and was a little tired.
Giuliani also commented on his own personal health and said he got tested two days ago and will be tested again "probably tomorrow."
Giuliani said he tested negative and currently has no symptoms of COVID-19.
ABC News' Ahmad Hemingway contributed to this report.
