The virus is thought to have emerged from illegally traded wildlife at a seafood market in Wuhan, the capital of Hubei province.
It causes severe acute respiratory infection and there is no specific cure or vaccine.
Meanwhile, Starbucks has closed half of its Chinese outlets, as the economic impact continues to grow.
Who is being evacuated?
Australian evacuees will be held on Christmas Island for two weeks, Prime Minister Scott Morrison said.
The announcement sparked controversy as the island is best known as an immigration detention centre, which has been criticised for its conditions and alleged human rights violations.
Currently only housing one Sri Lankan family of four, the facility was built to accommodate more than 1,000 people.
New Zealand will cooperate with Canberra to bring its 53 citizens home alongside the Australian evacuees.
Some 200 Japanese nationals have been flown from Wuhan and have landed at Tokyo's Haneda airport.
Around 650 others said they wanted to be repatriated, and the Japanese government said new flights were being planned.
According to Japanese media, several of the returnees were suffering from fever or coughs. All will be taken taken to hospital, regardless of whether they are showing symptoms.
They will then be tested in a quarantine ward before they can go home, and will be told not to leave their houses until the results are known.
Also on Wednesday, workers from the local US consulate, as well as some US citizens, left the city.
According to CNN, the evacuees might have to stay in isolation in an airport hangar for up to two weeks.
The UK Foreign Office is arranging to evacuate some 200 British people who wanted to leave the area. But some UK citizens have criticised the government, claiming lack of support in returning home.
Separately, two aircraft to fly EU citizens home were scheduled, with 250 French nationals leaving on the first flight.
South Korea said some 700 of its citizens would leave on four flights this week.
It's unclear whether they will be quarantined, but South Korean media are reporting the government will cover all costs of infected patients. So far, the country has four confirmed cases of the virus.
Meanwhile, Hong Kong announced plans to slash cross-border travel between the city and mainland China.
Wuhan - as well as the wider Hubei province - is already effectively in a lockdown with strict transport restrictions.
