American, United, Frontier and Southwest made the requests after social media posts described groups of terrified, crying children on flights.
Four major U.S. airlines — American, United, Southwest and Frontier — said on Wednesday that they did not want the government to use them to transport migrant children who have been separated from their families.
"We bring families together, not apart," American said in a statement, issued before President Donald Trump reversed the family separation policy. American said it had no knowledge that the government had in fact been using the airline to transport these children, but would be "extremely disappointed" to learn that it had. The airline provides travel to the government through contracts, but the government does not reveal details about the flights or their passengers, the statement said.
Following American's announcement, United, Southwest and Frontier released similar statements.
"Our company's shared purpose is to connect people and unite the world," United CEO Oscar Munoz said. "This policy and its impact on thousands of children is in deep conflict with that mission and we want no part of it."
In a Twitter post, Frontier said, "Frontier prides itself on being a family airline and we will not knowingly allow our flights to be used to transport migrant children away from their families."
In its statement, Southwest said it wanted no part of separating children from their parents, Reuters reported.
The moves come after a Facebook post said to be written by a flight attendant describing terrified, weeping migrant children on a flight from Phoenix to Miami went viral in the last few days.
Several other posts have followed, detailing stories of children who had no idea what was happening.
In response, Department of Homeland Security spokesman Tyler Houlton tweeted, "Buckling to a false media narrative only exacerbates the problems at our border and puts more children at risk from traffickers. We wish the airlines would instead choose to be part of the solution."
The Association of Flight Attendants-CWA, a union representing flight attendants in the United States, said it has asked airlines to discuss with employees what to expect if migrant children are on their flights and how to respond to passenger inquiries.
"This national discussion and response is being felt on our planes and discussed among the crews," the union said in a statement. "Some are struggling with the question of participating in a process that they feel is deeply immoral."
One American flight attendant, who asked to remain anonymous for fear of retribution, told NBC News on Wednesday that he had been on a flight from Dallas to Miami with what he believed was a group of migrant children. The children were 9 to 15 years old, looked Latino, did not speak English, and were accompanied by one adult escort, he said.
He said he had been on flights with deportees and asylum seekers before, but "those circumstances were different."
The escort seemed not to want him to speak to the children. "So just trying to get them a Coke, I felt so awkward in the presence of that escort," he said.
His suspicion that the children were migrants separated from their parents was confirmed, he said, when several colleagues posted on social media about similar experiences. Soon after, he and other American employees told supervisors that they objected to working on flights that transported migrant children and to the airline's participation in the process.
"It's gratifying to know that enough of us have reached out to leadership and they've responded in kind," he said. "We didn't know what their response would be."
The airlines' statements preceded Trump's signing of an executive order to end family separation at the border following intense criticism domestically and around the globe. It is unclear whether there will be more flights required to transport migrant children.