Homeland Security officials said on Tuesday that there was a 28% drop in the number of migrants encountered by Customs and Border Protection last month, amid a crackdown on migrants by Mexico.

For the first time this year, the number of migrants apprehended by immigration authorities after crossing the Southwest border dropped in June.

There were 104,344 people encountered in June, down from 144,278 the month before. Homeland Security officials said the numbers of single adults, families, and unaccompanied minors encountered at the border had all declined. The tally includes apprehensions between ports of entry as well as people who were deemed “inadmissible” by Customs officers.

Last month, the Trump administration had put pressure on Mexico to do more to stop the migrant flow, and President Trump threatened tariffs unless Mexico acted.

Since then, Mexico has deployed National Guard and federal police to secure its northern and southern borders, and it has agreed to expand what’s known as the Remain in Mexico program, which requires asylum-seekers to wait in Mexico for their day in a U.S. immigration court.

“Since the administration reached a new agreement with Mexico, we’ve seen a substantial increase in the number of interdictions on the Mexican southern border,” DHS said in its statement.

Acting Homeland Security Secretary Kevin McAleenan said he expected the numbers to be down, and said it was more than just a seasonal decline—Mexico’s efforts were making an impact.

The volume of people crossing the border has overwhelmed facilities. Border Patrol routinely is now holding as many as 20,000 people at a time when 4,000 is considered at capacity.

“We are still in an ongoing border security and humanitarian crisis,” the department said in a statement. “We are past the breaking point and in a full-blown emergency. This situation should not be acceptable to any of us.”

Includes reporting from The Associated Press

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