MELBOURNE (Reuters) - Prime Minister Scott Morrison said Australia will deny entry to all foreign nationals travelling from mainland China from Saturday due to the increasing threat from the coronavirus epimedic.

Morrison also announced that Australia was raising its travel guidance for China to the highest level, advising people against visiting the country at all.

"We're in fact operating with an abundance of caution in these circumstances," Morrison told reporters in Sydney. "So Australians can go about their daily lives with confidence."

The new incoming travel ban includes anybody who has been in China from Feb. 1, whether they have travelled directly from the country or through another port. It extends an existing ban on travel from the province of Hubei, the centre of the epidemic, to the entire country.

Australian citizens and permanent residents returning home are exempt from the ban but are required to isolate themselves for 14 days after their arrival.

Australian authorities have identified 10 coronavirus cases in Australia, but no deaths.

The Australian travel restrictions came just hours after the United States announced border curbs on foreign nationals who have been in China amid fears that the virus could spread further overseas.

Around two dozen countries have reported confirmed cases of the virus, but the vast majority of those infected remain in China, where the number of deaths stood at 259 on Saturday.

Qantas Airways and Air New Zealand both said on Saturday they were suspending direct flights to mainland China. Australian Foreign Minister Marise Payne said the government continued to work with Qantas to arrange flights to evacuate some Australian nationals from Hubei, as other countries have done. Asked if he expected any political fallout from the decision to close Australia's borders, Morrison said his "first responsibility is Australians and Australia's national interests."

"Obviously, we appreciate the challenges that the Chinese government are facing at the moment with this very serious issue, and we do thank them for the engagement we have had."