In a televised address on Wednesday, he said all travel from Europe would be suspended for the next 30 days.
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 1,135 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,” Mr Trump said.
“The new rules will go into effect Friday at midnight,” he added.