The US has suspended all non-essential traffic across its borders with both Mexico and Canada as it battles to control the coronavirus outbreak.
The curbs take effect at midnight on Saturday but will not affect trade, Secretary of State Mike Pompeo said.
Meanwhile, Illinois joined California in ordering residents to stay at home, while New York state ordered non-essential businesses to close.
Countries around the world are stepping up restrictions to combat the virus.
The virus has claimed more than 220 lives in the US and infected more than 16,000 people.
Globally nearly 250,000 patients have tested positive for the respiratory illness and more than 10,000 have died.
As both the number of cases and the global death toll continued to soar, many countries and regions took new measures on Friday, including:
- Spain: The government warned that army patrols would catch people outside without good reason
- Bavaria: Germany’s second most populous state became the first state in impose a lockdown
- France: police said patrols at Paris railway stations had been reinforced to stop people going on trips for the weekend
- Indonesia: a state of emergency will be in force in the capital Jakarta from Monday – bars, cinemas and many other businesses will be shut down.
Why did the US restrict border traffic?
President Donald Trump said on Friday: “Our nation’s top health care officials are extremely concerned about the grave public health consequences of mass, uncontrolled cross-border movement.”
He added: “Every week, our border agents encounter thousands of unscreened, unvetted and unauthorised entries from dozens of countries.”
Earlier this week President Trump announced that the border with Canada would be closed to non-essential traffic “by mutual consent”.
During Friday’s news conference, Mr Pompeo said the restrictions would take effect on Saturday and also apply to Mexico. They are due be in place for at least 30 days.
US citizens “should arrange immediate return” unless they intend to remain abroad for a time, Mr Pompeo said.
Acting Homeland Security Secretary Chad Wolf said the US was “working with both our Canadian partners as well as our Mexican partners”.
He added: “We want to make sure cargo continues, trade continues, healthcare workers continue to be able to traverse that border. But tourism, some recreational activities and other things need to stop during this crisis.”
Also on Friday, Canadian Prime Minister Justin Trudeau said asylum seekers crossing into the country on foot from the US would be turned back as part of the border shutdown.
What measures are the states taking?
New York State governor Andrew Cuomo ordered all “non-essential workers” to stay at home across the state from Sunday evening.
Public gatherings are also restricted across the state. The measures come as confirmed coronavirus cases in New York reached 7,000 – the highest in the US.
“These provisions will be enforced,” Mr Cuomo told reporters. “These are not helpful hints.”
New York and its neighbouring states of New Jersey, Connecticut and Pennsylvania also issued a joint order on Friday for the closure of all “personal care” businesses, such as hair and nail salons and piercing and tattoo parlours.
All outdoor team sports such as basketball games are also banned under the measures, which take effect on Sunday night.
The announcement comes after California Governor Gavin Newsom issued a similar order, telling all residents to stay at home.
He estimated more than half of the 40 million people in his state would contract Covid-19 in just the next two months.
Illinois has also ordered all residents indoors with exceptions to shop for food and medicine or take exercise.
Nevada announced its own ban on non-essential businesses on Tuesday. President Trump has so far ruled out any nationwide lockdown.