White House officials barred the media from conducting audio or video coverage of a critical briefing on Tuesday about the novel coronavirus' spread within the US.

CNN's Jim Acosta asked Vice President Mike Pence, who conducted the briefing, why it wasn't public and Pence responded, "I expect we'll be back on camera tomorrow."

The New York Times' Katie Rogers also asked and wasn't given a clear answer.

Pence told reporters at the briefing that there are now 77 domestic cases of coronavirus and nine domestic deaths, with three reported on Tuesday.

President Donald Trump has downplayed the threat of a potential pandemic, contradicting repeated warnings from US healthcare workers.

Visit Business Insider's homepage for more stories.

White House officials prohibited media outlets from doing audio or video coverage of a briefing on Tuesday about the spread of the novel coronavirus in the US.

The New York Times' Katie Rogers asked why the briefing wasn't public and wasn't given a clear answer.

CNN's Jim Acosta also asked Vice President Mike Pence, who conducted the briefing, why audio and video coverage wasn't allowed Pence responded, "I expect we'll be back on camera tomorrow."

According to Rogers, Pence told reporters there are now 77 domestic cases of coronavirus and nine domestic deaths, with three reported on Tuesday. There are confirmed cases of coronavirus in thirteen states plus New York City for a total of 14 jurisdictions, Rogers tweeted.

The vice president also reportedly made it clear that any American can be tested for the virus, without restrictions, if a doctor orders it.

He added that the Office of Management and Budget will direct all federal agencies to review travel policies and adhere to the State Department's travel advisories.

Pence said the White House task force for coronavirus will meet with the heads of major airlines on Wednesday to discuss "greater cooperation," Rogers tweeted.

Earlier Tuesday, New York governor Andrew Cuomo confirmed a second case of coronavirus in the state involving lawyer in his 50s who lives in Westchester County, just outside of New York City, but works in Manhattan.

The man recently traveled to Miami but has not been in contact with anyone who recently came from China or other global hotbeds for the virus, raising the possibility of "community spread" in the state of New York. He is currently hospitalized in Manhattan.

Dr. Anthony Fauci, the head the National Institute of Allergy and Infectious Diseases, said during Tuesday's briefing that public health professionals are prioritizing safety as they work on developing a coronavirus vaccine.

"Even though we're going at rocket speed, it's going to be at least a year to a year-and-a-half where we say, 'We have a product, let's rev it up and give it.'"

Fauci reiterated that point after Alex Azar, the Secretary of Health and Human Services, told reporters that scientists had developed a potential coronavirus vaccine "within three days," and that the Food and Drug Administration authorized the "entry of that vaccine into Phase 1 clinical trials" on Monday.

Immediately after, Fauci stepped in and cautioned the public that what Azar described was only the first phase of vaccine development.

"The whole process is going to take a year, a year and a half, at least," Fauci said as he stood a few feet away from President Donald Trump, who has largely downplayed the virus' threat within US borders.

One CDC official said during Tuesday's briefing that "we've got to stay grounded in data."

"We can't see the future. We really don't know this virus very well," the official said. "What we do know for sure is that in the right settings, it does have the potential to move quickly."

Asked about the stock market's reaction to coronavirus, Pence said, "We really feel the fundamentals of the economy are strong."

His comments came as the Dow Jones plummeted more than 700 points on Tuesday, even after the Federal Reserve issued an emergency rate cut to sooth investors' concerns.

Jerome Powell, the chairman of the Fed, said during a press conference that the coronavirus could impact economic activity "for some time."