The US is among a number of countries which have imposed tough travel restrictions against China as the coronavirus outbreak escalates.
Washington has faced criticism by Beijing after it moved to bar entry to most foreigners who have visited China in the past two weeks.
Australia has imposed similar measures, following Japan and Singapore.
Many major airlines, including British Airways, have also suspended flights with mainland China.
Meanwhile, Russia, Mongolia and North Korea have announced that they will close their land borders with the country to guard against the spread of the virus.
The increased border controls come as the number of people killed by coronavirus in China rose to 294 and confirmed cases passed 12,000.
The infection's rapid spread recently prompted the World Health Organisation (WHO) to declare it a global emergency .
The virus originated in the Chinese central city of Wuhan at the end of last year and has since spread to every province across mainland China.
While no deaths have been reported outside China, cases have been confirmed across at least 25 countries, including the US, Russia, France, Australia and the United Arab Emirates.
America has declared a public health emergency and President Donald Trump has signed an order barring entry to foreign nationals, other than immediate family of citizens and permanent residents, who visited China within the last 14 days, which scientists say is the virus's longest incubation period.
China has hit out at the US restrictions, which it said contradicted the WHO's appeal to avoid travel bans.
WHO Secretary-General Tedros Adhanom Ghebreyesus said despite the emergency declaration, there is "no reason for measures that unnecessarily interfere with international travel and trade".
US citizens returning from China will be allowed into the country, but will face screening.
The 195 Americans evacuated earlier this week from Wuhan were the subject of the first federal quarantine ordered since the 1960s.
Currently housed at a military base in southern California, none have so far shown signs of illness, although infected people do not show symptoms immediately.
One of those quarantined is Matthew L McCoy, a theme park designer who lives in China.
He said: "All of us really want to stay here and make sure we're all medically clear and the public safe."
US Health and Human Services Secretary Alex Azar said: "The risk of infection for Americans remains low and with these and our previous actions we are working to keep the risk low."
It comes as Apple said it was temporarily closing all stores in mainland China out of "an abundance of caution".
Meanwhile, British health officials are urgently trying to trace those who came into contact with the first two people diagnosed with coronavirus in the UK, one of which is a student at the University of York.
Public Health England confirmed that the two people taken ill - who are members of the same family - had been staying at a hotel in York when they became unwell.
The UK evacuated 83 Britons and 27 non-UK nationals from Wuhan, the centre of the outbreak, on Friday.
The British passengers were taken to Arrowe Park Hospital on Merseyside to be housed in isolation in an NHS staff accommodation block.
A number of other countries, including Australia, South Korea, India and Singapore are also quarantining evacuees for two weeks to avoid spread of the virus.
The vast majority of the cases have been in Hubei province and its provincial capital, Wuhan, the epicentre of the outbreak.
Chinese officials have postponed the end of the Lunar New Year holiday in the region to in a bid to curb travel and prevent the spread of infection.
Chinese premier Li Keqiang said they would coordinate with local governments to stagger the times when
people are asked to go back to work.
He also called on the EU to help with the provision of medical supplies.
China first informed WHO about cases of the new virus in late December.
Symptoms include fever, a cough and in more severe cases shortness of breath or pneumonia.
The number of coronavirus cases worldwide has surpassed that of the previous SARS epidemic, although death rates are lower.