President Donald Trump and first lady Melania Trump are in isolation with what is reported as "mild" symptoms after announcing overnight that they tested positive for COVID-19.

White House Dr. Sean Conley wrote in a memorandum: "This evening I received confirmation that both President Trump and first lady Melania Trump have tested positive for the SARS-CoV-2 virus. The President and First Lady are both well at this time, and they plan to remain home at the White House during their convalescence."

"Tonight, @FLOTUS and I tested positive for COVID-19," Trump tweeted overnight. "We will begin our quarantine and recovery process immediately. We will get through this TOGETHER!"

Top aides observed the president not feeling his best, as he appeared exhausted and fatigued, multiple sources told ABC News, following a rally that Trump cut short on Wednesday.

Given the intensity of his rally schedule, some believed his fatigue was as a consequence of being on the road, while others began to think it could be coronavirus.

While it is not clear how  the 74-year-old Trump, contracted the virus , the news comes just four hours after it was revealed that one of his closest advisers, Hope Hicks, had also tested positive.

Hicks traveled with Trump to Ohio for the debate on Tuesday and to Minnesota for a rally on Wednesday.

(With input from agencies)