(The Hill) — President Joe Biden appeared to make light of testing positive for COVID-19 in a fundraising pitch aimed at technology billionaire Elon Musk.

“I’m sick,” the president said in a post on the social platform X Wednesday after the White House said Wednesday evening that the president had tested positive for COVID-19.

“Of Elon Musk and his rich buddies trying to buy this election,” Biden said in a reply to his post after a two-minute delay, alongside a link to a fundraising webpage. “And if you agree, pitch in here.”

White House press secretary Karine Jean-Pierre said in a statement that Biden is “experiencing mild symptoms” and “will be returning to Delaware where he will self-isolate and will continue to carry out all of his duties fully during that time.”

“The President presented this afternoon with upper respiratory symptoms, to include rhinorrhea (runny nose) and non-productive cough, with general malaise. He felt okay 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 president’s doctor said in a statement.

Biden’s aim at Musk comes after the Wall Street Journal reported earlier this week that Musk said he will give $45 million monthly to a pro-Trump super PAC. The tech billionaire endorsed former President Trump after he survived an assassination attempt at one of his rallies in Pennsylvania this past weekend.

“I fully endorse President Trump and hope for his rapid recovery,” Musk said in a post on X, which he owns.

The Hill has reached out to Musk.