More than 65,000 unaccompanied child immigrants have been detained this year.
Obama, Biden to discuss immigration with heads of Guatemala, Honduras and El Salvador.
Officials acknowledge many people coming to U.S. think they'll be allowed to stay.
A draft says if 5,000 applied; 1,750 might be accepted and would cost $47 million.
Rep. Randy Weber said it's time to "hold our southern neighbors accountable."
Sens. Mark Warner (D-Va.) and Tim Kaine (D-Va.) urged the Obama administration to ensure that El...