The death toll from the coronavirus has risen to 259 and the number of confirmed cases of infection has increased to 11,791, Chinese authorities said.

The increases come as the US declares a public health emergency and takes steps towards stricter rules on entry into the country.

US Health and Human Services Secretary Alex Azar announced that President Donald Trump will temporarily bar entry to the US of foreign nationals believed to be a risk of transmitting the virus.

“The risk of infection for Americans remains low and with these and our previous actions we are working to keep the risk low,” Mr Azar said.

The new restrictions will begin on Sunday afternoon.

Australian airline Qantas has also announced that it will be suspending its direct services to China from February 9 until March 29 as a result of the outbreak.

The announcements followed that of the World Health Organisation (WHO) about the outbreak, which has spread to more than a dozen countries.

The vast majority of the cases have been in Hubei province and its provincial capital, Wuhan, the epicentre of the outbreak.

No deaths have been reported outside China.

China first informed WHO about cases of the new virus in late December.

Eighteen other countries have since reported cases, as scientists race to understand how the virus is spreading and how severe it could become.