New York City mayor Bill de Blasio traveled to the U.S.-Mexico border with more than 20 other mayors Thursday and was turned away from an immigrant detention facility in Tornillo, Texas.

“This is our federal government denying access, and not allowing information, and it’s not America. It’s crazy,” de Blasio told reporters as he stood outside the gates of Tornillo Migrant Children’s Facility.

“I’ve never seen anything like this,” he continued. “These are public facilities paid for with taxpayer dollars. How on earth are we not allowed to see what’s happening to these children? It’s astounding, and it feels really un-American.”

A report revealed Thursday that the Tornillo facility only holds teenage illegal immigrants who entered the U.S. unaccompanied — and thus is not a symbol of the Trump administration’s “zero tolerance” policy which has separated some children from their parents after crossing the border illegally.

The New York City Mayor asked a guard if he could meet with employees of the facility to “see what’s going on,” inside — but was denied.