McAllen, Texas — There’s much speculation surrounding the origin story of the migrant caravan and who’s leading it, which is now in southern Mexico en route to the U.S.

One group helps explain who’s in it, who’s behind it and why threats by the president won’t stop it.

“We’re not letting them out,” President Trump told Fox News Monday. “What happens is they would catch and release. We’re catching, we’re not releasing.”

In a renewed warning to migrants in the caravan, the president called on 5,200 additional troops to the border and assured that families seeking asylum are not being released into the U.S.

Meanwhile in McAllen, hundreds of Central American migrant families continue to be released to the Catholic Church. A few dozen people were seen walking to the local bus station with bus tickets to travel to their final destinations.

The president wants is to hold immigrant families in tent cities – like the children in Tornillo, Texas – while asylum is being determined. A process that can take months.

“We’re going to have tents, they’re going to be very nice and they’re going to wait and if they don’t get asylum they get out,” said Trump.

A Nicaraguan man – who preferred not to share his name – said he respects any decision the president takes on asylum seekers and any laws in the US.

He said he traveled for weeks with his wife and son, fleeing political persecution and death threats, so he had to do something.

The threats by the president come amid various unverified claims he has made, including the claim that many criminals might have joined the caravan. The administration has resorted not only to the military to try to dissuade them, but also vowed to cut aid to Central American countries.

“Nobody on the caravan cares if Trump eliminates aid,” said Pueblo Sin Fronteras Project Coordinator Alex Mensing.

PSF is a non-profit group that has aided other migrant caravans with orientation and supplies.

Mensing assures no one is calling the shots but the migrants.

“By no stretch of the imagination are we or any other organization telling people where to go,” he said.

“These are people who’ve left everything behind, nobody paid them to do that, they have no other options.”

About 1,600 migrants have chosen to stay in Mexico, while a few hundred have returned to their countries according to Mexican immigration authorities. There’s reportedly about 3,500 others in the caravan still determined to reach our southwestern border.