Melania Trump has visited Texas facilities where migrant children separated from their parents are being detained.
The first lady met doctors, social workers and those providing medical and educational services to some of the 2,300 children split from their families on the US-Mexico border, amid controversy over the detention of migrant children.
The visit was made after images of children housed in barren cages were broadcast, prompting outrage across the political spectrum.
Donald Trump has since reversed the policy of separating migrant families with an executive order.
At a round table discussion on Thursday, Mrs Trump thanked staff at the Upbring New Hope Children's Center for what she called their "heroic work".
"We all know they are here without their families and I want to thank you for your hard work, your compassion and your kindness you're giving them in these difficult times," she said.
"I would also like to ask you how I can help these children to reunite with their families as quickly as possible."
Mrs Trump visited two facilities, one used to hold families on arrival and a second where children are housed for a longer period.
The latter currently houses 60 children aged between five and 17, the majority of whom were not separated from their parents but arrived on their own, according to a senior official.
They added the goal was to place children at the facility with an "appropriate sponsor", and that they would be held for about 58 days before being placed with their parents, other relatives, or in foster care.
During Mrs Trump's visit, the president reiterated his belief that Democrats were to blame for child separations – because they refuse to cooperate on bringing in the immigration changes he demands.
Speaking from the White House he said the opposition party was in favour of an "extremist open border".
"We have to house these minors and we have to house them safely," he said. "And we should be returning them back home."
His executive order bringing to an end the practice of separating families has been criticised by campaign groups. They say it means families would be detained together indefinitely, and point out it does little to ensure the reunification of parents and children already split up at the border.
The trip was the idea of Mrs Trump, according to her spokesperson, who said the first lady was driven by her interest in children's welfare to see the situation for herself.
The White House previously said the first lady had worked behind the scenes to persuade her husband to soften his approach.
But Mrs Trump has been criticised for wearing a khaki jacket emblazoned with the phrase "I really don't care, do u?" on her way to the centre.
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Her spokesperson said there was "no hidden message".
"After today's important visit to Texas, I hope the media isn't going to choose to focus on her wardrobe."