The Biden administration has deported more than 2,000 Haitians since last week, a nearly even mix of single adults and families, out of the more than 12,000 that have been apprehended in a small Texas town by border officials, according to internal accounts.

The deportation of Haitian migrants is a stark example of how President Biden has deployed some of the most aggressive approaches to immigration put in place by former President Donald J. Trump.

The temporary camp in Del Rio has grown with staggering speed in recent days during a massive surge in migration that has overwhelmed the authorities.

Weeks after their dramatic escape from Kabul, tens of thousands of Afghans hoping to be resettled in the United States remain on military bases across the country and overseas as medical and security screenings slow the process.

The filing described “shockingly deplorable” conditions at two emergency shelters set up in Texas to handle the surge of children crossing the southern border.

Some of the children say they can wait more than a month before meeting with someone who can help connect them with a family member or other sponsor inside the United States.

As the Biden administration continues to grapple with high numbers of migrant families streaming across the southwestern border, efforts taken earlier this year to relieve overcrowding at border stations are resulting in the unintended release of thousands of undocumented migrants into the country, some of whom are off the radar of immigration enforcement officers.

United States officials said Friday that the number of migrants arriving at the southwestern border last month was the largest in years, a sign that the surge this year may extend into the hotter summer months when numbers typically start dropping.

President Biden came under renewed pressure on immigration Friday as the authorities said the largest number of migrants in years arrived at the border with Mexico last month and a federal judge in Texas raised legal questions about an Obama-era program that protects young immigrants from deportation.

Ed Gonzalez, the sheriff of Harris County, Texas, made ending a partnership with Immigration and Customs Enforcement one of his first decisions on the job because, he said, the program encouraged “illegal racial profiling.”