US President Donald Trump has announced all travel from Europe to the United States is suspended for 30 days due to the COVID-19 coronavirus outbreak.
The travel ban doesn't include the United Kingdom.
Trump made the decision to "keep new cases from entering our shores".
"The new rules will go into effect Friday at midnight (local time). These restrictions will be adjusted subject to conditions on the ground," he said from the Oval Office.
"I will never hesitate to take any of the necessary steps to protect the health, safety and wellbeing of the American people."
Trump said no nation "is more prepared or resilient" than the US.
He is also "confident" that the US will reduce the threat of the virus by imposing these "tough" measures.
"From the beginning of time, nations and people have faced unforeseen challenges, including large scale and very dangerous health threats. This is the way it always was and always will be. It only matters how you respond and we are responding with great speed and professionalism."
- Chinese foreign ministry spokesperson says United States military may have taken coronavirus to Wuhan
- COVID-19 spread mostly by people showing no symptoms - European scientists
- Jacinda Ardern expecting advice on border restrictions after Donald Trump's Europe travel ban
- Coronavirus COVID-19 declared pandemic by World Health Organization
Also during his address, Trump said he will provide emergency economic relief for Americans impacted by COVID-19.
"To ensure that working Americans who are impacted by the virus can stay home without fear of financial hardship, I will soon be taking emergency action, which is unprecedented, to provide financial relief.
"This will be targeted for workers who are ill, quarantined or caring for others due to coronavirus. I will be asking Congress to take legislative action to extend this relief."
Trump has also cancelled trips to Colorado and Nevada out of "caution". He was meant to travel there at the end of the week.
"Out of an abundance of caution from the coronavirus outbreak, the President has decided to cancel his upcoming events in Colorado and Nevada," White House press secretary Stephanie Grisham said in a statement.
There are 1135 confirmed cases of COVID-19 in America and 38 people have died.