The event will feature "remarks to peaceful protesters for law and order" by the president, according to an invite obtained by ABC News and confirmed by two White House sources familiar with the planning.
The gathering is scheduled to take place on the South Lawn of the White House in conjunction with a previously planned event organized by controversial conservative activist Candace Owens' group Blexit, a campaign to urge Black Americans to leave the Democratic Party, sources said.
Trump according to a source is expected to address the crowd from the balcony of the White House.
With just days separating the president from his stay at Walter Reed Medical Center, experts fear this type of event threatens to exacerbate the crisis already engulfing the White House and further spread the disease. On Wednesday, ABC News reported that the coronavirus outbreak had infected "34 White House staffers and other contacts" in recent days, citing an internal government memo.
"All attendees must bring a mask with them and will be instructed to wear it on the White House Complex," a source familiar with the planning of the event told ABC News. "All attendees must submit to a Covid-19 screening tomorrow morning. This will consist of a temperature check and a brief questionnaire. The health and safety of all attendees is our priority and following CDC guidelines is strongly encouraged."
"The Trump administration continues to have disregard for the science," said Dr. Jay Bhatt, an ABC News contributor and practicing internist. "This statement is premature given that we don't know what will happen between now and Saturday given that symptoms can pop at any time. He put many people at risk and we saw the aftermath. This can't happen again."
The Trump campaign also announced a rally on Monday night in Sanford, Florida. On Twitter, the president referred to it as "a very BIG RALLY!"
The Biden camp quickly responded to the news, with Mike Gwin, Biden's deputy direct response coordinator, saying in a statement, "Donald Trump seems to be living in an alternate reality where he isn't sick and contagious with COVID-19 and where he didn't just hold what Dr. Fauci himself described as a super-spreader event at the White House that likely infected dozens more. This decision is stunningly reckless and irresponsible, and it's only the latest evidence that Trump has waved the white flag of defeat against this virus even as it kills thousands of Americans each week and batters our economy."
Dr. Sean Conley, the president's personal physician, said in a Thursday night press release that "Saturday will be day 10 since [Trump's] Thursday diagnosis" and opened the door to Trump hosting public events again after they were canceled following his diagnosis.
"Based on the trajectory of advanced diagnostics the team has been conducting," Conley continued, "I fully anticipate the president's safe return to public engagements at that time."
The White House and Conley have faced criticism for deliberately misleading the American people, offering conflicting statements about the president's health status and treatment timeline after he tested positive -- leading to a crisis of credibility regarding those tasked with informing the public on the president's health.
News of the event -- and the number of expected attendees -- is sure to reignite concerns that the White House has not taken the steps necessary to stem the disease's spread.
Dr. John Brownstein, a Harvard epidemiologist and ABC News contributor, said that "while the president continues to show improvements, we must remain vigilant about his health."
"We know that this illness can take unexpected sharp turn and providing such a positive forecast may only provide a false sense of security," Brownstein said.
Several attendees of a Rose Garden ceremony to name Amy Coney Barrett as the next Supreme Court nominee two weeks ago have since tested positive – including the president, who was being treated at Walter Reed Medical Center last weekend.
ABC News' Elizabeth Thomas contributed to this report.