By Stephanie Stahl

PHILADELPHIA (CBS) — President Donald Trump tweeted in the overnight hours that he and First Lady Melania Trump tested positive for the coronavirus. It comes just after news emerged that senior aide Hope Hicks had contracted COVID-19.

A White House spokesperson says the president is experiencing “mild symptoms” associated with the virus, but did not give specifics.

Medical experts say Trump, who is 74 years old, clinically obese, and has elevated cholesterol, is at higher risk of serious complications from a virus that has killed more than 205,000 Americans.

No treatments are currently approved to prevent illness in someone newly infected.

The White House has canceled all of the president’s public events on Friday.

In a tweet just before 1 a.m., Trump announced both he and the first lady have tested positive for COVID-19.

“We will begin our quarantine and recovery process immediately. We will get through this together!” the president tweeted.

The stunning development came hours after Trump confirmed to Fox News that Hicks, one of his closest aides, had tested positive for the coronavirus.

“She tested positive, and I just went out with a test. I’ll see, because you know we spend a lot of time, and the first lady just went out with a test,” Trump told Fox News prior to the news about his diagnosis. “So whether we quarantine or whether we have it, I don’t know.”

White House physician Dr. Sean Conley released a statement, saying the president and first lady were both doing well.

“Rest assured I expect the president to continue carrying out his duties without disruption while recovering,” Conley said.

Hicks had traveled to several events with Trump this week, including the debate on Tuesday and to his rally in Minnesota on Wednesday.

Trump attended a fundraiser in New Jersey on Thursday and reportedly spent time in close contact with a number of his supporters.

“Wishing Donald Trump and First Lady Melania Trump a speedy and complete return to good health,” New Jersey Gov. Phil Murphy tweeted.

Philadelphia Health Commissioner Dr. Thomas Farley says the president is “at some level of risk.”

The White House says, the president’s daughter, Ivanka Trump, her husband, Jared Kushner, and the president’s son, Barron, have all tested negative.

“First, let me wish the president and first lady well. Certainly, given his age, he’s at some level of risk but most people do recover from this infection. Let’s hope that is the case,” Farley said.

Pennsylvania Democratic Sen. Bob Casey tweeted, “COVID-19 is a serious illness that has impacted millions of American families. I wish President Trump and First Lady Melania Trump a speedy recovery following their positive test. I will keep them in my prayers.”

Meanwhile, Pennsylvania Republican Sen. Pat Toomey tweeted, “Sending along best wishes to the president and first lady on a ful and speedy recovery.

Stephanie Stahl