American Airlines announced Tuesday that it will suspend flights to China and Hong Kong through the end of April, a month longer than the carrier had previously planned.

In making the announcement, the airline cited waning demand because of concerns about the coronavirus outbreak.

American offers direct service to Shanghai and Beijing from Los Angeles and Dallas-Fort Worth International airports. It also flies directly between Hong Kong, Dallas and Los Angeles.

Flights between Los Angeles and Dallas to Shanghai and Beijing will be suspended through April 24; service between Dallas and Hong Kong will be suspended through April 23 and flights between Los Angeles and Hong Kong will be suspended until April 24. The airline had previously canceled flights through the end of March.

American, along with two other U.S. carriers, began canceling service between the United States and mainland China at the end of January after the State Department raised its China travel advisory to Level 4, its highest level of caution. Delta already announced that it will cancel flights to China through the end of April. United Airlines said flights would be canceled through the end of March, but officials said they continue to evaluate the situation.

Travel between the United States and China has been all but shut down as officials work to contain the spread of the coronavirus, now known as covid-19. So far, 13 cases have been confirmed in the United States.

Since Feb. 2, U.S. citizens who have spent time in Hubei province, the epicenter of the outbreak, are subject to a mandatory two-week quarantine, while foreign nationals are prohibited from entering the United States. All incoming flights from China are being directed to 11 U.S. airports so passengers can undergo enhanced screening. Travelers arriving from other cities in China are being screened and asked to self-quarantine for 14-days.