U.S. President Joe Biden, under fire from fellow Democrats to drop his re-election campaign, tested positive for COVID-19 while on a trip to Las Vegas on Wednesday and is self-isolating after experiencing mild symptoms, the White House said.

White House press secretary Karine Jean-Pierre announced the positive test for the 81-year-old Democrat after Biden canceled a speech due to the diagnosis.

“He is vaccinated and boosted and experiencing mild symptoms,” Jean-Pierre said.

As he boarded Air Force One to depart Las Vegas to recuperate in Delaware, Biden told reporters: “Good, I feel good.”

The illness comes at a crucial time for Biden, who has been losing ground in battleground states against Republican Donald Trump, who is headlining a triumphant convention this week after he survived an assassination attempt on Saturday.

The White House said Biden planned to spend a long weekend at his Delaware beach house. It was unclear how long the sickness would keep him for the campaign trail.

Minutes after the announcement, the president’s motorcade was on the move from taping a radio interview in Las Vegas to the Las Vegas airport. The president was returning to Delaware to isolate, the White House said.

Biden had greeted a couple of dozen people at a Mexican restaurant prior to going into the radio interview. He was running late to deliver a speech to Latino civil rights group UnidosUS when the organizer, Janet Murguia, announced he had tested positive for COVID-19.

There were groans in the conference room at the news.

“He said to tell my folks that we’re not going to get rid of him that quickly, we’re going to have a chance to hear from him in the future directly,” Murguia said.

The White House cited Biden’s doctor as saying he had been suffering from upper respiratory symptoms earlier in the afternoon.

“He felt OK for his first event of the day, but given that he was not feeling better, point-of-care testing for COVID-19 was conducted and the results were positive for the COVID-19 virus,” the statement said.

The White House said Biden will be self-isolating in according with the U.S. Centers for Disease Control guidelines.

His symptoms are mild and he has received an initial dose of Paxlovid, the doctor said.

Proofreading by Uchechi Ojo, Sub-editor at Neptune Prime.