CAPITOL HILL — A political battle is brewing in Washington over the dramatic surge of unaccompanied children who are crossing the southwest border into the United States. Republicans blame the Obama administration for what they describe as lenient and confusing immigration policies, while Democrats say the children are fleeing extreme poverty and drug-related violence. The White House has dismissed suggestions to put troops on the border with Mexico.

So far this year, 52,000 unaccompanied children, mostly from Guatemala, El Salvador and Honduras, have made the long journey across Mexico to cross the border into the United States. U.S. border patrol agents detain most of them and eventually place some of them with a relative or foster family in the U.S.

The Chairman of the House Homeland Security Committee, Republican Michael McCaul, said the Obama administration should have seen this coming.

"The tragic fact is these children are making a dangerous journey based on misinformation and the false promise of amnesty," said McCaul.

McCaul, from Texas, said border states like his are completely overwhelmed by the influx of children, and he is calling on the president to take action.

"States should not need to protect what is in the federal government’s role under our Constitution. The president needs to immediately send the National Guard to the Southwest border to deal with this crisis," said McCaul.

The White House rejected putting guard troops on the border after announcing last week the federal government would open additional detention centers.

Democrats rejected blame for the situation, saying Central American children are also seeking refuge in other countries.

"It is irresponsible to attribute this crisis to one U.S. policy, or for that matter to one U.S. president," said Rep. Bennie Thompson, a Democrat.

Many of the children who come across alone are eventually released to the custody of relatives with instructions, pending court appearances. Some are deported.

Homeland Security Secretary Jeh Johnson calls it a humanitarian crisis.

"We are talking about large numbers of children without their parents who have arrived at our border, hungry, thirsty, exhausted, scared and vulnerable. How we treat the children, in particular, is a reflection of our laws and our values," said Johnson.

But some Republican lawmakers are frustrated, saying they have been calling for more fences and tougher security along the border.

"I have been there. I know what I am talking about. And we don’t have a fence down there, and if did, we would not have five-year-old children coming across,” said Rep. Mike Rogers, a Republican.

Secretary Johnson explained that U.S. law has special provisions for unaccompanied minors.

"The law that was created in 2008 requires that we turn these kids over, if they are unaccompanied, to the Department of Health and Human Services within 72 hours, generally," said Johnson.

Johnson said the U.S. is working to get the message out to parents in Central America that their children face unacceptable risks coming to the United States and that there are no immigration permits waiting for them.