A senior CBP official argued that June's decline was due partly to new border security measures put in place by Mexican and U.S. authorities following talks last month. | Eric Gay/AP Photo immigration Border arrests dropped sharply in June

The number of migrants arrested by Border Patrol at the U.S.-Mexico border fell 29 percent in June, signaling that a migrant surge that's taxed federal resources and ignited partisan battles on Capitol Hill may recede this summer.

Border Patrol arrested roughly 95,000 migrants in June, according to figures released Wednesday by Customs and Border Protection. That’s down from nearly 133,000 in May, the highest monthly total since March 2006.


Border arrests are a metric used widely to estimate the number of illegal border crossings.

A summer falloff in border arrests isn’t unusual. May-to-June declines occurred in nine of the last 10 years. But a senior CBP official argued Wednesday that June's decline was due partly to new border security measures put in place by Mexican and U.S. authorities following talks last month.

“I would attribute Mexico to making some difference,” the official told reporters on a background call.

The official cited Mexican efforts to stop migrants traveling in large groups — defined as more than 100 people — before they reach the U.S. Border Patrol intercepted 15 large groups in June, a sharp drop from the 48 groups encountered a month earlier.

“Seeing that downturn has had a very positive effect on our being able to deal with the capacity numbers and border security writ large,” the official said.

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Record numbers of migrant families trekked north from Guatemala, El Salvador and Honduras in recent months, an influx President Donald Trump argues is fueled by lax U.S. asylum and deportation laws. But migrant advocates and Democrats contend that violence and poverty in those countries forced people to leave, and that Trump’s hard-line policies exacerbated a humanitarian crisis.

The influx of migrants overwhelmed federal authorities, prompting fierce criticism of squalid conditions at certain processing centers and shelters for unaccompanied children.

Even as Congress approved a $4.6 billion funding package to deal with the crisis in late June, news reports of overcrowding and other problems at an El Paso-area processing center where children are detained outraged Democrats. An inspector general’s office report released earlier this month found similar problems in South Texas facilities, and NBC News reported Tuesday on child sexual abuse allegations and unsanitary conditions in an Arizona border station.

The CBP official said Wednesday that the lower border arrest totals and the $4.6 billion funding package improved the agency’s ability to provide temporary housing and care for families and unaccompanied children.

The official said CBP currently had approximately 200 unaccompanied children in its custody, down from a peak of up to 2,700 at one point in May. The overall number of people in CBP custody had dropped to up to 11,000 in June, down from 19,000 in May.

The Health and Human Services Department — which received more than half the border funding — has taken children into custody more quickly and relieved pressure on temporary CBP facilities, the official said Wednesday.

“We’re short-term detention, we are not long-term detention,” the official said. “Our goal is to get these individuals out of our custody as quickly as possible to HHS so they can have all the proper care and long-term needs met.”

The latest border figures will likely influence a planned assessment next week of whether new U.S. and Mexico enforcement measures have been effective.

Following Trump’s late May threat to slap Mexican goods with tariffs, officials from the U.S. and Mexico reached an agreement on June 7 to step up immigration enforcement. Under the deal, Mexico pledged to deploy 6,000 members of its newly formed National Guard to intercept migrants and the U.S. said it would expand a program that sends non-Mexican asylum seekers to Mexico pending the outcome of their U.S. asylum cases.

In a side deal reached during those negotiations, Mexico also agreed to engage in talks over a bilateral or regional asylum pact if the current set of actions fail to produce results.

The decline of arrests in June was assisted by a drop in families and unaccompanied children.

Border Patrol arrested roughly 57,000 families in June, down from 85,000 a month earlier, according to CBP. Agents picked up approximately 7,000 children, a decrease from 11,500 in May.