Alan Gomez

USA TODAY

The number of children caught crossing the southwest border into the USA continues to plummet, which could alter the federal government's response to the crisis.

Border Patrol agents in the Rio Grande Valley in Texas apprehended 522 children traveling without their parents last week, a sharp decline from June when agents routinely caught about 2,000 children a week, according to Department of Homeland Security data released Thursday.

Agents apprehended 5,508 unaccompanied children in July, the lowest number since February. Agents caught more than 10,000 children traveling without their parents in May and again in June.

The Border Patrol caught 7,410 adults traveling with children in July, compared with 16,330 caught in June and 12,774 caught in May.

Department of Homeland Security Secretary Jeh Johnson said he is encouraged by the "good news" of fewer children crossing the border, but the numbers remain too high.

"We continue to have much work to do to address this issue, and our message continues to be clear: Our border is not open to illegal migration," Johnson said in a statement. "Unless you qualify for some form of humanitarian relief, we will send you back consistent with our laws and values."

The summer heat is raging throughout Mexico, possibly discouraging parents from sending their children on the long, dangerous journey that can involve lengthy walks and rides atop trains.

Obama administration officials, including Vice President Biden, have traveled to Central America to discourage parents from sending their children on the trek, warning that they will be deported despite rumors that they'll be able to stay.

Immigration courts have started speeding up the cases of children caught traveling alone or with their mothers, a message that could be making its way back to Central America. Johnson said the added focus on deporting people quickly has led to more flights sending people back home and has cut down the removal time for adults from 33 days to four.

The rush of children, mostly coming from the Central American countries of Honduras, Guatemala and El Salvador, prompted a massive government response and reignited the immigration debate in Washington. President Obama requested $3.7 billion to beef up border security and provide better care for the children while in U.S. custody, but Congress adjourned for its August recess without approving any new funds.

Still, the waves of children — more than 43,000 have been caught from Central America this fiscal year — have become a central issue as legislators return to their home districts and prepare for the elections in November.