Oregon Sen. Jeff Merkley posted a video showing he was denied entry to an immigrant detention center housing children who had been separated from their parents.

Merkley chronicled his efforts to enter the former Walmart in Brownsville, Texas, in a Facebook post on Sunday. The senator says he made the trip after his office's attempt to schedule a visit was declined.

"I think it's unacceptable that a member of Congress is not being admitted to see what is happening to children whose families are applying for asylum. I decided to come out here, go up to the door and ask to be let in," he said in the video.