FILE - Unaccompanied migrant children, from ages 3 to 9, watch television inside a playpen at the U.S. Customs and Border Protection facility in the Rio Grande Valley in Donna, Texas, March 30, 2021.
FILE - Unaccompanied migrant children, from ages 3 to 9, watch television inside a playpen at the U.S. Customs and Border Protection facility in the Rio Grande Valley in Donna, Texas, March 30, 2021.

Tens of thousands of migrants continue to arrive at the U.S.-Mexico border weekly, but for the first time in months the number of unaccompanied minors held by the U.S. Border Patrol has dipped below 1,000, down from more than 5,000 a month ago, according to U.S. officials.

Earlier this week, Homeland Security Secretary Alejandro Mayorkas reported an 88% drop since March 28 in the number of migrant youths being kept at U.S. Customs and Border Protection (CBP) facilities that for months have been strained beyond capacity.

The sharp decline constitutes the first concrete sign of progress in an early and thorny challenge for the Biden administration, which has faced criticism from lawmakers of both political parties amid a sharp rise in migrant arrivals at America’s southern border.

In a statement Mayorkas hailed what he termed “dramatic” results, adding, “We remain committed to this critical mission.”

Recent months have seen severe overcrowding at CBP facilities, which are the first stop for migrants encountered at the border and are not designed to care for children.

U.S. policy has long been to transfer migrant youths within 72 hours to the custody of the Office of Refugee Resettlement under the Department of Health and Human Services (HHS) and place them in specialized facilities designed to accommodate children’s needs. From there, unaccompanied minors are typically released to family members living in the United States or into foster care.

For months, inadequate capacity at HHS facilities delayed transfers from CBP beyond the 72-hour window, causing migrant youth populations at CBP stations to rise. As of Tuesday, there were 22,000 children under HHS care.

The Biden administration said it is solving the problem by expanding HHS facilities and mobilizing federal caseworkers to expedite reuniting children with a verified family member.

As a result, the administration says holding times for migrant youths at CBP facilities has shrunk from an average of five days to just 20 hours.

Immigrant advocates welcomed the developments but noted hurdles remain for migrant youths.

“After their release, the next challenge these children will face will be their need for an attorney to help them make their case for U.S. protection,” said Megan McKenna, a spokesperson for Kids in Need of Defense, an advocacy group for unaccompanied minors.

While many Democratic lawmakers have cheered the administration’s recent steps on immigration, Republicans on Capitol Hill remain sharply critical.

An asylum-seeking migrant girl is carried by a Department of Public Safety agent while her mother is disembarking from an inflatable raft after crossing the Rio Grande river into the United States from Mexico in Roma, Texas, May 5, 2021.

South Carolina Republican Senator Lindsey Graham suggested the massive federal effort to accommodate migrant minors serves to draw more unauthorized border crossers.

“The new Biden Administration policy of processing all 16-year-old and younger unaccompanied minors in the United States has led to a dramatic increase in unaccompanied minors showing up at our border,” Graham tweeted earlier this week.

The Biden administration has exempted minors from a pandemic-related emergency measure implemented by the former Trump administration that blocked people of all ages from seeking asylum in the United States.

Migrant border arrivals, including unaccompanied children, rose late last year and have accelerated further in the early months of 2021.