The White House on Tuesday warned airlines that it may suspend all China-U. S. flights if the coronavirus outbreak becomes a bigger public health threat to the United States.

In a meeting with airline executives Tuesday afternoon, White House officials said they are not banning flights yet but said they will assess the situation daily, leaving open the possibility of a ban, people with knowledge of the meeting said.

Airlines have already canceled hundreds of flights scheduled from China’s Wuhan international airport in recent days, giving U.S. health officials a respite as they focused on the logistics of rerouting U.S.-bound travelers from the region to one of five airports for special screening.

Travelers from Wuhan are being funneled to airports in Atlanta, Chicago, Los Angeles, New York and San Francisco, where they are being screened for the virus. If cleared, they are allowed to continue to their final destination, officials with the U.S. Centers for Disease Control and Prevention said.

The new strain of coronavirus has killed at least 132 people and sickened nearly 6,000 in China.

Infections have been confirmed in France, Germany, South Korea, Japan, Nepal, Cambodia, Singapore, Vietnam, Taiwan, Canada, Sri Lanka and the United States.

The State Department has issued a Level 4 advisory for Wuhan, meaning “no American should travel to Wuhan while this virus continues to have impact,” Vice President Pence said Monday. Later Monday, the State Department issued a Level 3 travel advisory for all of China, urging Americans to reconsider or postpone travel to any part of the China.

Public health officials continue to say the coronavirus poses a low risk to the American public, but say the enhanced screenings at five airports are part of “proactive preparedness precautions.”

Officials familiar with Tuesday’s meeting between the airline executives and the White House said the White House made clear that any decision to ban flights will be based on the public health threat.

Health and Human Services Secretary Alex Azar on Tuesday described the outbreak as “fast moving, constantly changing,” and said senior officials are keeping a close on the outbreak to respond and keep Americans safe.

“Americans should know that this is a potentially very serious public health threat, but at this point Americans should not worry for their own safety,” he said.