Citing violence in Central America as the reason for a substantial increase in border crossings by unaccompanied minors, senior administration officials admitted Monday they weren't expecting undocumented immigrants to pour in on such a massive scale.

U.S. authorities have been overwhelmed by a wave of unaccompanied minors crossing the border in the Rio Grande valley of America's southwest. Most are coming from El Salvador, Guatemala, and Honduras, where violent crime is prevalent.

The trend of unaccompanied and undocumented minors combined with a large number of mothers with young children have overwhelmed the ability of Immigration and Customs Enforcement to process them. Many are being dropped off at bus stations in Arizona by the Department of Homeland Security. Though they are processed and referred for hearings as part of removal proceedings, for the 60,000 minors expected to be apprehended this year alone the progression through the immigration framework becomes more difficult.

Currently, unaccompanied minors are turned over to the Department of Health and Human Services within 72 hours after Homeland Security officials interview process, begin removal proceedings and try to determine if the minor has any family or suitable sponsors in the United States.

The children are kept at facilities such as the Fort Sill, Okla., Army post. Meanwhile, those needing legal representation are assisted by the Justice Department and partner AmeriCorps.

On June 2, FEMA Administrator Craig Fugate was selected to oversee and direct federal efforts along the border in the Rio Grande valley. President Obama also has requested $1.4 billion from Congress in additional funding to go toward the government's effort to help and process unaccompanied minors.

Thus far, the efforts to stop undocumented, unaccompanied minors have been limited to public messaging campaigns and regular communications with the nations of origin, and a greater push on the part of the Obama administration for Congress to pass immigration reform.