US President Donald Trump and wife Melania have tested positive for Covid-19, the president said in a tweet early on Friday morning.
The news came after it was announced on Thursday that senior Trump aide Hope Hicks had tested positive.
The stunning development comes a month before the US election on 3rd November.
Mr Trump is now expected to be in quarantine for some two weeks while facing treatment for the disease.
US Vice President Mike Pence tweeted that he’s praying for the president.
MSNBC host Rachel Maddow, who frequently criticises the president, encouraged people to pray for him.
Greg Swenson, a Christian and spokesperson for Republican Overseas, has encouraged people to pray for Mr Trump "the same way the prayed for Boris".
"The best thing to do is pray that he doesn't have any symptoms. That might be a stretch given that he's 74-years-old, but pray for him, pray for his family, pray for the country.
"Pray, that he doesn't suffer, and that Mrs Trump doesn't suffer and hope that he can maintain a schedule and keep some optimism in the country."
Swenson said the Covid diagnosis, just one month away from Election Day, will pose psychological and practical problems.
"This will be a really interesting opportunity for the President to maintain his positive attitude, his ability to fight for Americans, and in this case, fight for himself, but I don't think he'll change very much at all. There might be some changes in voter perceptions. Maybe there's a sympathy vote, maybe there's a 'I told you some vote from the haters on the left'.
"But I think the more important issue is the practical [aspect]. He has his ability to generate enthusiasm at live events and campaign rallies. I think they just have to do their best to convert to a basement strategy like the vice president has.
"I think, in general before he has any sort of symptoms, and hopefully he has a quick recovery, he'll be right back at it, he'll just have to do it electronically."
The president's age puts him at higher risk of serious complications from the virus.
Sean Conley, physician to the president, said: "The President and First Lady are both well at this time, and they plan to remain at home within the White House during their convalescence.
"The White House medical team and I will maintain a vigilant watch, and I appreciate the support provided by some of our our country's greatest medical professionals and institutions.
"Rest assured I expect the President to continue carrying out his duties without disruption while recovering, and I will keep you updated on any future developments."
The positive tests for the Trumps come as stark reminders that the coronavirus continues to spread, even as Mr Trump has tried desperately to suggest it no longer poses a danger.
Since it emerged earlier this year, Mr Trump, the White House and his campaign have played down the threat and refused to abide by basic public health guidelines - including those issued by his own administration - such as wearing masks in public and practising social distancing.
Instead, Mr Trump has continued to hold campaign rallies that draw thousands of supporters.
On Thursday, he tweeted: "Hope Hicks, who has been working so hard without even taking a small break, has just tested positive for Covid 19. Terrible!
"The First Lady and I are waiting for our test results. In the meantime, we will begin our quarantine process!"
Ms Hicks who serves as counsellor to the president and travelled with him to a rally on Wednesday, tested positive on Thursday.
The 31-year-old is the closest aide to Mr Trump to test positive so far.
The virus has killed more than 200,000 Americans and infected more than seven million nationwide.
Ms Hicks travelled with the president multiple times this week, including aboard Marine One, the presidential helicopter, for a Minnesota rally on Wednesday, and aboard Air Force One to Tuesday night's first presidential debate against Joe Biden.
Multiple White House staffers have tested positive for the virus, including Katie Miller, Vice President Mike Pence's press secretary, as well as one of the president's personal valets.