Biden announced last week that immigrants from Cubans, Nicaraguans, Haitians and Venezuelans will be sent to Mexico if they enter the US illegally.
Several hundred people marched through the streets of El Paso, Texas ahead of US President Joe Biden's first visit to the southern border.
Demonstrators spoke out against new restrictions aimed at cracking down on illegal border crossings.
Biden announced last week that Cubans, Nicaraguans, Haitians and Venezuelans would be sent to Mexico if they enter the US illegally – an expansion of a pandemic-era immigration policy called Title 42.
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.
Around 300 migrants have sought refuge outside El Paso's Sacred Heart Church, with many afraid to seek shelter elsewhere.
The US President is scheduled to arrive in El Paso Sunday afternoon before travelling on to Mexico City to meet with North American leaders on Monday and Tuesday.