President Donald Trump has suspended travel from Europe to the United States, except for the UK, for 30 days starting on Friday as he responded to mounting pressure to take action against the spread of the coronavirus.
The president took the dramatic step in a sombre Oval Office speech as he battles to address the health and economic shocks to Americans from the sometimes fatal virus and responds to criticism he has not taken the threat seriously enough.
Trump also announced several economic steps aimed at cushioning the blow to American businesses struggling with a sudden loss of consumer demand.
"This is the most aggressive and comprehensive effort to confront a foreign virus in modern history," he said on Wednesday night.
"I am confident that by counting and continuing to take these tough measures, we will significantly reduce the threat to our citizens, and we will ultimately and expeditiously defeat this virus."
Trump walked back his remarks suggesting that "trade and cargo" from Europe would also be banned, tweeting moments after the speech that "trade will in no way be affected" by the travel restriction. "The restriction stops people not goods," he said in the tweet.
US stock futures slid further as the president spoke, down more than 4 per cent and signalling another day of losses awaits Wall Street.
Trump, whose re-election bid on November 3 could hinge on how well he responds to a crisis that has suddenly enveloped his presidency, stopped short of declaring a national emergency.
He is facing criticism from Democrats for not moving quickly enough to provide testing for Americans to determine whether they have the contagion.
Trump pulled no punches in saying Europe was partly to blame for the virus' spread in the United States, where it has killed at least 37 people and infected 1281.
His travel restrictions on Europe were similar to what he declared on travel from China earlier this year when the illness was spreading wildly there.
"The European Union failed to take the same precautions and restrict travel from China and other hot spots. As a result, a large number of new clusters in the United States were seeded by travellers from Europe," he said.
Trump signed an order that suspends the entry of most foreign nationals who have been in certain European countries at any point during the 14 days prior to their scheduled arrival to the United States.
The order did not apply to legal permanent residents, immediate family members of US citizens, and other individuals who are identified in the proclamation.
Trump said the restrictions will be adjusted subject to conditions on the ground.
As the US stock market took another hit from the virus on Wednesday, Trump said he would take emergency action to provide financial relief for workers who are ill, quarantined or caring for others due to the illness.
He said he was instructing the Treasury Department to defer tax payments without interest or penalties for certain businesses and individuals affected.
Trump added he was also instructing the Small Business Administration to provide capital and liquidity to firms affected by the virus.