Countries surrounding China, including Mongolia, Russia and Singapore, have moved to shut down their borders. But some officials from the Center for Disease Control and Department of Health and Human Services have expressed concerns about imposing such a measure in the United States, the people said.
Mr. Trump, sources familiar with his thinking said, has been concerned about the economic impact of any travel restrictions. Speaking at a factory in Michigan on Thursday, Mr. Trump played down concerns about the coronavirus, saying it would have a “very good ending for us” and that “hopefully it won’t be as bad as some people think it could be.”
On Thursday, the State Department raised its travel advisory to Level 4 — “Do not travel” — and the World Health Organization declared a global health emergency because of the spreading virus. The rating is reserved for situations in which the government expects to have very limited ability to help citizens abroad.
American Airlines said its decision to suspend flights was informed by the State Department advisory. The union representing the airline’s pilots had sued American on Thursday, seeking an end to the flights, citing “known and unknown risks” in its lawsuit.
Airlines had already begun limiting service to China this week, offering fee waivers for those traveling to the country. In its statement, Delta said customers whose flights were affected could get information from the My Trips section of the Delta site to understand how to request a refund and rebook their travel after April 30.
Major cargo companies — United Parcel Service, FedEx and DHL — said that they were monitoring the spread of the virus and that they had urged employees to take basic safety precautions. DHL said services in Hubei Province — which includes Wuhan, the city at the center of the virus outbreak — had been suspended because of strict controls put in place by the local government.
In a research report this week, DHL warned that should local lockdowns in China extend into February, they could affect the supply chains of sectors including automotive, pharmaceutical and medical supplies, and high-tech manufacturing for the optical electronics and semiconductors industries. This week, Tesla, the electric-car maker, said production at its new Shanghai factory could be affected by a local order calling for a temporary halt to operations.