Coronavirus updates: New cases on the rise in 49 states, territories

Dr. Scott Atlas, an adviser on the White House coronavirus task force, has apologized after appearing on a Russian state-funded television network to criticize lockdown measures aimed at curbing the spread of COVID-19.

Atlas addressed the matter via Twitter on Sunday, saying he was "unaware" that RT was a registered foreign agent.

"I regret doing the interview and apologize for allowing myself to be taken advantage of," Atlas tweeted. "I especially apologize to the national security community who is working hard to defend us."

Atlas, a neuroradiologist who was handpicked by President Donald Trump to join the coronavirus task force in August, told RT during a lengthy interview on Saturday that he considered the pandemic to be largely under control and that lockdowns are actually "killing people."

RT, formerly called Russia Today, is registered under the Foreign Agents Registration Act, a U.S. law that applies to people or companies disseminating information in the United States on behalf of foreign governments, political parties and other "foreign principals."

U.S. intelligence agencies have alleged that RT, which broadcasts around the world in English, served as a propaganda outlet for the Kremlin as part of efforts to influence the 2016 U.S. presidential election. Russia denies interfering.

Prince William, Duke of Cambridge, tested positive for COVID-19 in April, royal sources told ABC News.

Wiliam's diagnosis came around the same time his father, Charles, Prince of Wales, also tested positive for the disease. Charles is the heir apparent to the British throne while his eldest son, William, is second in line.

The Court Circular, the official record of past royal engagements, shows that William had a joint engagement with his wife, the Duchess of Cambridge, on April 8 via Zoom. He did a solo virtual engagement -- without Kate -- the following day. His next joint engagement wasn't until May 7.

ABC News' Zoe Magee contributed to this report.

President Donald Trump suggested to a Florida rally that he may fire Dr. Anthony Fauci, the nation's top expert on infectious diseases and a leading member of the White House coronavirus task force.

Speaking to the crowd after midnight early Monday morning, the president was complaining about the news media coverage of the coronavirus pandemic when rally-goers began chanting, "Fire Fauci!"

"Don't tell anybody, but let me wait until a little bit after the election," Trump responded. "I appreciate the advice."

"He's been wrong a lot," the president told the crowd of Fauci. "He's a nice man though."

Fauci has served as the director of the National Institute of Allergy and Infectious Diseases for over 30 years.

Trump's comments come after Fauci's hard-hitting interview with The Washington Post in which he criticized the U.S. government's response to the coronavirus pandemic, including Dr. Scott Atlas, a neuroradiologist and the president's hand-picked adviser on COVID-19.

Nearly 50,000 people across the United States remain hospitalized for COVID-19.

As of Sunday, the number of current hospitalizations nationwide was 47,502, according to data collected by The COVID Tracking Project.

That figure has been steadily climbing since mid-September.