Biden due to visit US Mexico border

Several hundred migrant supporters have marched through El Paso, Texas, ahead of US President Joe Biden's politically sensitive visit to the country's southern border

Biden is scheduled to arrive in El Paso on Sunday before travelling on to Mexico City to meet with North American leaders on Monday and Tuesday.

Around 300 migrants have taken refuge on footpaths outside an El Paso church, some of them afraid to seek more formal shelters, advocates say, amid new restrictions meant to crack down on illegal border crossings.

The president announced last week that Cubans, Nicaraguans, Haitians and Venezuelans will be expelled to Mexico if they enter the US illegally -- an expansion of a pandemic-era immigration policy called Title 42.

The new rules will also include offering humanitarian parole for up to 30,000 people a month from those four countries if they apply online and find a financial sponsor.

Dylan Corbett, who runs the nonprofit Hope Border Institute, said immigration enforcement agencies have already started ratcheting up deportations to Mexico, and he senses a rising level of tension and confusion.

"It's a very difficult situation because they (migrants) can't go forward and they can't go back," he said. People who aren't processed can't leave El Paso because of US law enforcement checkpoints; most have travelled thousands of miles from their homelands and refuse to give up and turn around.

"There will be people in need of protection who will be left behind," Corbett said.

The new restrictions represent a major change to immigration rules that will stand even if the US Supreme Court ends a Trump-era public health law that allows US authorities to turn away asylum-seekers.

El Paso has swiftly become the busiest of the Border Patrol's nine sectors along the US border with Mexico.

Large numbers of Venezuelans began showing up in September, drawn to the relative ease of crossing, robust shelter networks and bus service on both sides of the border, and a major airport to destinations across the United States.

After Mexico agreed to accept Venezuelans who'd crossed the border illegally, Nicaraguans have since taken their place.

Title 42 restrictions have been applied 2.5 million times to deny migrants a right to seek asylum under US and international law on grounds of preventing the spread of COVID-19.