About 350 Americans who left Wuhan, China, aboard two planes arrived at a US military base in California on Wednesday, in Washington's latest effort to fly its citizens away from the epicenter of the coronavirus outbreak.

The US travellers on two State Department-chartered flights will be quarantined for 14 days after landing, the US Defence Department said in a statement.

The jets landed at Travis Air Force Base, about midway between San Francisco and Sacramento, KNTV television reported, showing images of two planes on the tarmac on its website.

One of the planes will continue on to Miramar Marine Corps Air Station in San Diego after refueling, the Pentagon said, and was due to arrive at Miramar between 6 a.m. and 9 a.m. Pacific time (between 1400 and 1700 GMT), a Marine Corps spokesman said in a statement.

The State Department separately said it may stage additional flights on Thursday but gave no other details.

The United States and other countries are seeking to evacuate their citizens from China, where the fast-spreading outbreak has killed 490 people. Two deaths have been reported outside of the mainland.

US health officials have reported 11 confirmed cases of the virus in the United States so far, including two person-to-person transmissions.

The Trump administration declared a public health emergency on Jan. 31, and announced the extraordinary measures of barring the entry of foreign nationals who have recently visited China and imposing a mandatory two-week quarantine for travelers from China's affected province.

The State Department issued a ‘Do Not Travel’ to China advisory to US citizens, advising them to return on commercial flights if possible, though some commercial airlines have suspended flights to or from major Chinese cities.

US officials have also restricted flights from China to 11 designated airports deemed capable of carrying out enhanced screening.

Nearly 200 Americans were evacuated late last month, mostly US diplomats and their families, and they were flown to March Air Force Base east of Los Angeles.