Biden returns to White House after COVID-19 diagnosis to prep for Wednesday's Oval Office speech

July 23 (UPI) -- President Joe Biden returned Tuesday afternoon to the White House ahead of his address to the nation the next day as he continues to recover from COVID-19 after announcing the end of his bid for re-election.

In a updated letter Tuesday on Biden's health, Dr. Kevin O'Connor , physician to the president, said Biden's symptoms "have resolved" and he "continues to perform all of his presidential duties."

Biden was self-isolating since Wednesday at his vacation home in Rehoboth Beach, Del., after he tested positive for the virus following a campaign event in Las Vegas and a rushed trip back to the east coast.

"Over the course of his infection, he never manifested a fever, and his vital signs remained normal, to include pulse oximetry," O'Connor's update read . "His lungs remain clear" and Biden's BINAX rapid antigen testing "is negative."

His return to the White House will be Biden's first public appearance since ending his campaign, which he did via letter and statement. It arrives as the now outgoing president is set to address the nation 8 p.m. EDT Wednesday from the Oval Office about his historic decision as a candidate for re-election.

Biden posted on social media later Tuesday morning that his speech will focus on "what lies ahead, and how I will finish the job for the American people" since bowing out of the race on Sunday.

In addition to giving a detailed explanation for his exit, Biden will talk about the work ahead in the remaining months of his presidential term, NBC News reported.

He took ill as pressure mounted for him to end his campaign following his dismal debate performance last month against former President Donald Trump that raised questions about his health and mental capacity.

On Sunday, while recuperating, Biden announced he would not seek re-election and then endorsed his vice president, Kamala Harris , to take his place at the top of the ticket.

The Harris campaign has reportedly raised more than $100 million since Biden's Sunday announcement and his endorsement of her to take his place.

According to the White House press pool , Biden was slated to arrive at the White House on the South Grounds at 2:3 p.m. local time Tuesday. A half hour later, he will receive the daily briefing, which is closed to the press.

On Monday, Biden thanked his campaign staff for their hard work in a call to the Wilmington, Del., office as Harris met with them for the first time as the likely Democratic presidential nominee. He acknowledged in the call that it was hard for the staff to hear he was ending his campaign but assured them it was "the right thing to do," urging them to embrace Harris.

O'Connor said Monday in a letter that Biden had received his 10th dose of the COVID-19 Paxlovid oral pill that morning and his symptoms had "almost resolved completely."

"His pulse, blood pressure, respiratory rate and temperature remain absolutely normal," Monday's letter read. "His oxygen saturation continues to be excellent on room air. His lungs remain clear."