Three busloads of migrants were dropped off outside the Washington DC home of US vice-president Kamala Harris late on Christmas Eve, the latest episode in an escalating battle between the Joe Biden White House and the governors of southern Republican states over federal immigration policy.

The Central and South American migrants, believed to be sent from Texas, were dropped off in below-freezing temperatures, with some wearing only sweatshirts and shorts.

Texas’s far-right governor, Greg Abbott, has previously sent buses to Harris’s Naval Observatory home. An organizer with the Migrant Solidarity Mutual Aid Network, Amy Fischer, told local news station ABC7 that Abbott orchestrated the drop off as a political stunt.

“It really does show the cruelty behind governor Abbott and his insistence on continuing to bus people here without care about people arriving late at night on Christmas Eve when the weather is so cold,” Fischer said.

The group took the travelers to the shelter of a local church where they were given warm food and clothes.

Tatiana Laborde with Samu First Response, an aid group that was also there to meet the buses, said that similar drops had been made in Washington since April. “Christmas Eve and freezing cold weather is no different,” Laborde told CNN. “We are always here welcoming folks with open arms.”

The arrivals were the latest salvo in an effort by Abbott to force the Biden administration to step up immigration controls at the US border with Mexico. Florida’s governor Ron DeSantis and Arizona’s governor Doug Ducey have also transported migrants to cities that are run by Democrats.

“You and your administration must stop the lie that the border is secure and instead immediately deploy federal assets to address the dire problems you have caused,” Abbott wrote in a letter to Biden last week.

Abbott added: “You must execute the duties that the US constitution mandates you perform and secure the southern border before more innocent lives are lost.”

On Friday, US Customs and Border Protection reported that 233,740 migrants were apprehended at the southern border in November, marking the highest number ever recorded for the month. The border agency reported that of 204,000 “unique encounters”, 35% were from Cuba and Nicaragua.

In a statement released on Saturday, the federal homeland security department said it “continues to fully enforce our immigration and public health laws at the border”.

“As temperatures remain dangerously low all along the border, no one should put their lives in the hands of smugglers, or risk life and limb attempting to cross only to be returned,” the Department of Homeland Security added, warning that “anyone attempting to enter without authorization is subject to expulsion” under the policy known as Title 42.

Last week, the US supreme court temporarily suspended the expiration of the policy empowering border officials to turn away asylum seekers on public health grounds. The Trump White House imposed it during the early phases of the Covid-19 pandemic.

Days before Title 42 was due to expire, the border city of El Paso, Texas, declared a state of emergency after migrant numbers surged. If allowed to expire, Abbott has warned that the number of people entering the US illegally “will only increase”.