"Do not send your children to the borders," Obama told ABC News. "If they do make it, they'll get sent back. More importantly, they may not make it."
Tens of thousands of unaccompanied minors, mostly from Central America, have crossed into the United States in recent months, overwhelming processing centers and leading to criticism of Obama's immigration policies from Republicans.
While US officials attributed the spike to poverty and rising gang violence in Central America, the US government has sought to dispel any notion by parents that their children might qualify to stay in the United States as part of immigration reform efforts before the US Congress.
"Our message absolutely is don't send your children unaccompanied, on trains or through a bunch of smugglers," Obama told ABC. "We don't even know how many of these kids don't make it, and may have been waylaid into sex trafficking or killed because they fell off a train."