US President Donald Trump says the US will suspend all travel from Europe to the United States for the next 30 days because of the Covid-19 coronavirus.

But he said the "strong but necessary" restrictions would not apply to the UK, where 460 cases of the virus have now been confirmed.

There are 1135 confirmed cases of the virus across the US, with 38 deaths.

"To keep new cases from entering our shores, we will be suspending all travel from Europe to the United States for the next 30 days," Trump said.

"The new rules will go into effect Friday at midnight," he added.

Trump said the speed of the spread of the virus in Europe showed him this drastic measures needed to be taken.

He said he would take emergency action to provide financial relief for workers who are ill, or caring for others, due to the coronavirus.

Trump urged Congress to pass tax relief measures in an attempt to combat the effect of the outbreak on the US economy.

"I am calling on Congress to provide Americans with immediate payroll tax relief," he said.

Trump said the situation was not a financial crisis.

After he announced the travel ban, US stock futures extended losses, down more than 2 percent.

If you have symptoms of the coronavirus, call the NZ Covid-19 Healthline on 0800 358 5453 (+64 9 358 5453 for international SIMs)

Read more about the Covid-19 coronavirus:

Covid-19: What you need to know Self isolation - your questions answered Timeline: virus's spread across the globe Scientific hand-washing advice to avoid infection More Covid-19 news