United Airlines announced on Tuesday that it is suspending 24 flights between China and the US in the first week of February amid coronavirus travel warnings.

"Due to a significant decline in demand for travel to China, we are suspending some flights between our hub cities and Beijing, Hong Kong and Shanghai beginning Feb 1 through Feb 8," United said in a statement.

The affected US hubs include San Francisco International, Newark Liberty International, Chicago O'Hare International and Washington Dulles International.

United said it usually operates 12 flights per day from the US to the Chinese mainland and Hong Kong. According to the reduction, between Feb 1 and Feb 8, three fights to Hong Kong, 10 flights to Beijing, and 11 flights to Shanghai would be canceled.

The 2019 novel coronavirus, first identified in Wuhan, in Central China's Hubei province, is an ongoing outbreak. The National Health Commission of China reported that as of Jan 27, there were 4,515 confirmed cases in 30 provinces; 106 deaths; 60 patients who have recovered; and 6,973 suspected cases.

The US Centers for Disease Control and Prevention reported five confirmed cases in the United States. The CDC issued a level 3 travel warning, urging US citizens to avoid all nonessential travel to China.

"We will continue to monitor the situation as it develops and will adjust our schedule as needed," United said in the statement.

Zong Yi in Washington contributed to this story.