Coronavirus: US declares health emergency, bars foreigners who visited China

US Health and Human Service Secretary Alex Azar has announced a public health emergency to minimise the risk of a coronavirus outbreak in the country. 

US President Donald Trump has ordered the ban of entry to foreign nationals - other than immediate family of US citizens and permanent residents - who have travelled in China within the last 14 days, Azar said. 

The travel ban is due to start on Sunday at 5 pm (0900 AEDT, Monday). 

Azar said that any US citizen who has visited China's Hubei province over the past two weeks and is returning to the US will be subject to a maximum 14-day quarantine. 

US citizens who are returning from the rest of mainland China will undergo "proactive" health screenings and up to 14 days of "monitored self-quarantine." 

"The actions we are taking and continue to take compliment the work of China and the World Health Organization," Azar said. "The risk of infection for Americans remains low". Separately, the US State Department said it is working with US and Chinese agencies to organise additional flights for US citizens to return to the United States from Wuhan, the epicentre of China's coronavirus outbreak. 

The effort comes as major US airlines said they were suspending all flights to mainland China. 

The State Department and White House did not comment on a report that the Trump administration was considering a mandatory order for all US citizens to leave the Wuhan region. 

The State Department official said "as space is available, seating will be offered to US citizens on a reimbursable basis, to leave from Wuhan Tianhe International Airport to the United States. All travellers will be screened for symptoms at the airport prior to departure." The State Department late Thursday boosted its travel advisory for China from a Level 3: Reconsider Travel to Level 4: Do Not Travel. 

Chinese authorities have suspended air, road, and rail travel in the area around Wuhan and the larger Hubei Province, and placed restrictions on travel and other activities throughout the country.