McALLEN, Texas (CBSNewYork/AP) — First Lady Melania Trump was in Texas on Thursday, visiting a facility that houses some of the 2,300 migrant children that have been separated from their families after crossing the southern border illegally.

“Be kind and nice to each other, OK,” she said as she left one classroom at Upbring New Hope Children’s Center and headed for another.

gettyimages 980367198 First Lady Melania Trump Visits Migrant Children At Texas Detention Center

First Lady Melania Trump participates in a round table discussion with doctors and social workers at the Upbring New Hope Childrens Center operated by Lutheran Social Services of the South and contracted with the Department of Health and Human Services June 21, 2018 in McAllen, Texas.(Photo by Chip Somodevilla/Getty Images)

In a written statement, Mrs. Trump said the visit had “impacted me greatly.” She called on Congress to work together on immigration legislation that would benefit the children.

“Spending time with them reinforces the fact that these kids are in this situation as a direct result of adult actions,” she said. “It is my hope that Members of Congress will finally reach across the aisle and work together to solve this problem with common sense immigration reform that secures our borders and keeps families together.”

The first lady’s stop in McAllen came one day after President Donald Trump signed an executive order to stop the separation of migrant families at the southern border.

Her visit to the facility was quickly arranged after Mrs. Trump decided earlier this week that she wanted to go, her spokeswoman said, adding that she wanted to lend support to children who have been separated from their parents. The center housed 55 boys and girls, ages 12-17, on Thursday, but only about six of them had been separated from parents, officials said. The other children were placed there after they crossed into the U.S. alone.

MORE: President Trump Signs Executive Order To Stop The Separation Of Migrant Families

“I’m here to learn about your facility,” the first lady said as she met with staff and federal health and border patrol officials. She asked how she could help “these children to reunite with their families as quickly as possible” and how often they communicate with their families. She learned the children are allowed a 10-minute phone call twice a week.

But as CBS2’s Jessica Layton reported, the visit also raised questions about Mrs. Trump’s choice of jacket, which she took off before going into the facility. On the back it read, “I really don’t care, do you?”

Her spokeswoman said there was no hidden message. However, the president later tweeted, saying the jacket referred to the “fake news media.”

The shelter is one of 100 in 17 states, including one in East Harlem that Mayor Bill de Blasio visited on Wednesday before he went to Texas, too.

“Just trying to get to the honest truth about what’s happening to these children,” he said.

De Blasio and mayors from across the country tried and failed Thursday to visit a shelter for separated children near El Paso.

Meanwhile, the president continues to blast the Democrats for the crisis at the border.

“They don’t care about the children… They don’t care about anything,” he said. “A massive child smuggling industry.”

Earlier in the day, it was House Republicans who voted to reject a conservative immigration bill.

Late Thursday night, the Trump administration said of the 2,300 children separated from their families since May, 500 hundred have now been reunited with their families. Meanwhile, the Pentagon says it plans to put up as many as 20,000 migrants on U.S. military bases.

(© Copyright 2018 CBS Broadcasting Inc. All Rights Reserved. The Associated Press contributed to this report.)