United States President Donald Trump has said he will invoke a statute in light of the coronavirus pandemic to block undocumented migrants from entering the US either from the northern or southern border, saying the crossings "threaten to create a perfect storm".

Trump made the announcement at a news conference on Friday, in which he also announced that the US and Mexico would restrict non-essential travel across their shared border in an effort to limit the spread of the new coronavirus.

Immigrants rights groups immediately condemned the move, saying it fuels "anti-immigrant sentiment".

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Any migrants entering the country through irregular routes along the land borders would immediately be turned backed under the measure, instead of being processed by US authorities.

Mexican Foreign Secretary Marcelo Ebrard said on Friday that Mexico will allow the US to return Mexican and Central American migrants caught trying to enter the US through unofficial routes.

Ebrard, however, said Mexico will not permit the US to send back migrants detained on the joint frontier who are not Mexican or Central American.

Around 120 migrants from the region are detained at the border every day, he said.

The new policy is set to go into effect Friday at midnight.

Agreement with Canada

Canadian Prime Minister Justin Trudeau also announced on Friday an agreement in which undocumented migrants crossing the border between the US and Canada will be returned to authorities from the country from which they crossed.

Trudeau called it an exceptional measure that will protect Canadians amid the pandemic.

There is a long-standing agreement between the US and Canada that requires those seeking asylum to apply in the first country they arrive in.

Under that agreement, if an individual crossed from the US at a legal Canadian port of entry, he or she would be returned and told to apply in the US. However, if the person requests asylum on Canadian soil at a location other than an official crossing, the process is allowed to go forward.

In most cases, refugees are released and allowed to live in Canada, taking advantage of social welfare benefits.

Many migrants cross the border into Quebec from Champlain, New York at Roxham Road, about 50 kilometres (30 miles) south of Montreal.

Canadian Minister of Public Safety Bill Blair said about 45 to 50 have been crossing irregularly each day, but on Thursday just 17 crossed. The government earlier announced that anybody crossing would have to be quarantined for 14 days.

Trudeau also further confirmed that all non-essential travel between Canada and the US will end at midnight Friday. The two countries announced the measure earlier this week.

'Stoking anti-immigrant sentiment'

Trump was slammed by immigrant rights groups and advocates over the move on Friday. The US president has been accused of "fuelling bigotry" for repeatedly calling COVID-19, the "Chinese virus", despite World Health Organization guidance to not tie the virus to groups of people, locations or certain ethnicities.

Following his decision on Friday, many also accused him of tying the virus's spread to irregular immigration, despite there being no evidence to support his assertion.

"Fueling xenophobia or stoking anti-immigrant sentiment by calling COVID-19 the “Chinese virus” or linking this health crisis to immigrants at the border is deliberately hateful," tweeted US Congresswomen Veronica Escobar.

"History shows that scapegoating of groups, especially in times of crisis leads to violence. We've seen far too much of that during your presidency. Stop it," she added.

History shows that scapegoating of groups, especially in times of crisis leads to violence. We've seen far too much of that during your presidency. Stop it.



Help us lead Americans out of this crisis instead of putting targets on their backs. — Rep. Veronica Escobar (@RepEscobar) March 20, 2020

In announcing the measure, Trump said that border agents have been dealing for decades with "unscreened, unvetted and unauthorised entries from dozens of countries".

"But now it's with the national emergencies and all of the other things that we've declared, we can actually do something about it," he said.

Immigrants rights advocate Julissa Arce Raya, tweeting after the announcement, said that Trump "is attempting to use a global pandemic - the virus already spreading within the borders of the United States - as a pretext to fulfill his most anti-immigrant promises".