"I'm here to support you and give my help, whatever I can" on "behalf of children and the families", Mrs Trump said as she sat down with officials at a US Border Patrol facility in Tucson, Arizona.
East Wing communications director Stephanie Grisham said the first lady's goal is to "learn and educate herself" about issues at the border, first hand, from those on the front lines and thank them for the sometimes unsafe work they do.
She went on to ask how often the border patrol agents see children crossing alone without an adult.
Similar to her visit to Tucson, the first lady took part in a round table where she heard from officials at the Phoenix facility. The court also prohibited, absent a waiver, the deportation of parents without their children, and it said that in the future children can only be separated from a parent if that parent poses a threat to the child.
However, the trip was largely overshadowed by the first lady's fashion choice.
"Mrs. Trump plans to visit additional facilities sometime this week", Grisham said, though she did not specify a day for the trip.
ABC's Lauren Pearle and Justin Doom contributed reporting to this article. She added that the First Lady wants to also be updated on the legal situation for migrant children, since it has changed in recent days.
Reporters following the first lady on the tour heard her say, "How are you?" to a little boy who was being held, along with his mother, in a cell marked "Family Unit 8". She later travelled to Phoenix, where she visited a complex that is housing dozens of migrant children separated from their parents.
"We're working with Congress, hopefully, to provide more resources and the ability to actually enforce the law", she said.
Communications director Stephanie Grisham said Mrs. Trump's goal is to "learn and educate herself" about issues at the border from those on the front lines and thank them for their work.
Southwest Key is a nonprofit that runs 26 immigrant shelter facilities for children across Texas, Arizona and California.
"Migration is a human right".
Over the past two months, about 2,300 children have been separated from their parents in Trump's "zero tolerance" policy on illegal crossing of the Mexican border.
U.S. president Donald Trump has made an about-turn on a policy that was a step too far - even for a presidency that has probed the outer limits of civility - by signing an order to stop the separation of children from parents who enter the United States illegally. It's not clear yet how the administration will meet the deadline.