Democratic Sen. Chris Murphy (Conn.) on Friday said he “fought back tears” during a visit to Customs and Border Protection (CBP) facilities with a bipartisan group of senators and Homeland Security Secretary Alejandro Mayorkas amid a rapid surge in migrants at the U.S.-Mexico border.

Murphy, a member of the Senate Foreign Relations Committee, on Twitter Friday detailed his experience, including when he visited a border processing facility in El Paso, Texas, where he said hundreds of children were “packed into big open rooms.”

“In a corner, I fought back tears as a 13 yr old girl sobbbed [sic] uncontrollably explaining thru [sic] a translator how terrified she was, having been separated from her grandmother and without her parents,” he tweeted.

Murphy clarified in a follow-up tweet that while kids are no longer being separated from their parents at the border, as they had been under former President Trump’s zero-tolerance policy, relatives traveling with the children who are not their parents are not allowed to stay with them.

The Connecticut senator further detailed his experience in the facilities, at which reporters were denied access, writing in another tweet that the “memory of that 13 yr old girl will be w [with] me forever.”

“The desperation these kids and families are fleeing is hard to describe,” he added. “So long as conditions are abysmal in places south, people will find a way to get here, no matter how high the wall is or how many border agents.”

While some lawmakers have argued that President Biden could be doing more to ensure safe access to asylum for young people at the border, Murphy tweeted Friday that he believed the administration is “trying their best to uphold the rule of law with humanity.”

“They have a ton of work ahead to clean up the mess Trump left them, but their intentions are true,” he added.

Murphy said that the trip Friday included a visit to Trump’s unfinished border wall, which the senator described as “unexpectedly devastating.”

“How did it come to this, that a country defined by our warm embrace of immigrants now must be defined by our irrational fear of them?” he tweeted. “We must be better.”

The recent surge in migrants, especially unaccompanied minors, at the southern border is on track to reach the highest number of attempted migrant crossings in two decades, Mayorkas said Tuesday.

Democrats have cited a variety of factors behind the recent surge, including economic hardships exacerbated by the coronavirus pandemic and border smugglers encouraging migrants to come to the U.S. under the new presidential administration.

However, Republicans have largely argued that Biden’s immigration policies are to blame, with GOP members of the House Judiciary Committee on Thursday calling for a hearing on “what the Biden Administration is doing to address the criminal activity caused by the Biden Administration’s radical policies.”