Updated at 6:53 p.m.

The White House accused Sen. Jeff Merkley of "smearing" law enforcement on Monday, a day after the Oregon Democrat posted video showing he had been denied entry to a Texas detention facility for migrant children.

The Facebook video went viral and had more than 1.3 million views by Monday evening.

White House deputy press secretary Hogan Gidley accused Merkley of "irresponsibly spreading blatant lies." Gidley asserted Monday that the senator's refusal to back President Donald Trump's hard-line agenda allowed criminals to enter and remain in the United States.

"No one is taking a public safety lecture from Sen. Merkley, whose own policies endanger children, empower human smugglers and drug cartels, and allow violent criminal aliens to flood into American communities," the spokesman said in a written statement.

Merkley's office fired back Monday afternoon, accusing the White House of "smearing" Merkley because "they can't defend their indefensible policy of snatching children from their 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. Posted by Senator Jeff Merkley on Sunday, June 3, 2018

Ray Zaccaro, the senator's communications director, said Merkley and his staff saw "children in cages" at a federal processing center Sunday morning in McAllen, Texas. The group then traveled 59 miles to Brownsville, where Merkley was barred from entering the detention facility.

Merkley said upward of 1,000 children are being held in the Brownsville center. "This is just not America," he told The Oregonian/OregonLive on Monday night. "We've never treated people in these circumstances seeking asylum as criminals. And we certainly have never separated children from their parents and exposed them to prison-like settings."

U.S. Attorney General Jeff Sessions announced in early May that the federal government would refer for prosecution all people suspected of crossing the border illegally, including asylum seekers. The announcement sparked immediate controversy, as it would lead to families being split apart.

Democrats have ripped the policy as draconian and damaging to young children, while Trump administration officials have sought to blame Democrats for allowing illegal immigration to flourish with lax policies.

The Brownsville facility is located in a former Walmart store and operated by Southwest Key Programs, which according to its website runs 27 shelters for immigrant children in Texas, Arizona and California.

The video shows Merkley was made to wait at the door, which had its glass panes blacked out, while an employee tried to track down a supervisor. Police arrived just as a supervisor came outside. The supervisor said he was not authorized to discuss the issue and referred Merkley to company administrators. He did not explain why the senator could not tour the facility.

The White House is attacking me because their cruel policy of stealing children from parents has no defense. They continue to hide what's happening in the detention centers. Americans deserve to know how innocent children are being traumatized in their name & w/ taxpayer dollars. — Jeff Merkley (@JeffMerkley) June 5, 2018

The operator of the Brownsville detention center told Merkley's people beforehand that he likely wouldn't be allowed to enter the facility. Instead, they asked for several weeks to prepare for a visit.

"If they're restricting access unless they get several weeks of notice, my question is, what are they hiding?" he said. "I have no desire to inspect some sort of Potemkin Village."

On Monday, Tyler Houlton, a Department of Homeland Security spokesman, said Merkley inquired about access to the facility, but that the request "presented obvious and serious privacy concerns" and could have disrupted operations.

The department contends that it worked to provide Merkley access to the building, and that the senator's entourage protested its inability to film the children housed there.

"Contrary to any misinformation campaign, the safety of children is paramount for DHS," Houlton said.

The war of words with the White House could further raise the profile of a senator who's more than once been mentioned as a possible presidential candidate. Speculation intensified in March when Merkley headlined a meeting of the New Hampshire Democratic Party's executive committee in March. New Hampshire is traditionally the nation's first primary state.

--Jeff Manning