US senator shared video of him being barred entry to immigration detention center in Texas, where children are separated from their parents.

Sen. Jeff Merkley (D-Oregon) visited a detention center for immigrant children near the Mexico border Sunday in an attempt to draw attention to the Trump administration policy of separating children from parents.

"I’m going to try to enter a facility in Brownsville, TX run by the Office of Refugee Resettlement. I am told that this former Walmart may currently be housing hundreds of refugee children who have been separated from their parents," Merkley said in a Facebook post. 

As the senator noted during his livestream, he was attempting to see firsthand the conditions inside the facility but he was denied. 

Merkley, accompanied by multiple video cameras and the American Civil Liberties Union,was reportedly told by an employee at the facility that he would be able to speak with a supervisor about the conditions at the detention center. When the supervisor came out of the building told Merkley that he was not allowed to make a statement. No member of Congress has visited the facility, says Merkley, who in the past two years has become one of the most vocal critics of Trump administration policies.

"Americans should be outraged by the fact that our taxpayer dollars are being used to inflict spiteful and traumatizing policies on innocent children," he said in a statement.

US Federal department announced last May 6 that it will file criminal charges against all foreigners who are caught crossing the border illicitly.

That measure, known as "zero tolerance," sends parents to jail and the children to refuges financed with federal funds and supervised by the Department of Health and Human Services.

At least 600 children were separated from their parents last month.

Thousands of people poured into the streets Friday in some 30 cities around the US to protest against the growing number of children separated from their parents at the Mexican border as a result of the zero tolerance policy promoted in May by US Attorney General Jeff Sessions.

Though the demonstration in Washington was the main one, throughout the day there were numerous protests in some 30 US cities including Los Angeles, New York and Chicago, and internationally in Barcelona, Spain, according to the organizers.