Three Central American nations have given their support to President Barack Obama's plea for help in tackling a surge in the number of people - particularly children - crossing the Mexico-US border.

The presidents of El Salvador, Guatemala and Honduras were all present for talks at the White House, aimed at bringing cross-border immigration under control. In a joint statement with Obama, they urged parents not to send their children on the potentially dangerous journey across Mexico and into the US, and pledged to crack down on "people smuggling" operations.

"We reiterated our commitment to prevent families and children from undertaking this dangerous journey and to work together to promote safe, legal, and orderly migration," the four said on Friday.

Obama had earlier told a gathering of Central American presidents at the White House that children would be sent home if they had no valid claim to stay in the US.

At least 57,000 unaccompanied minors have been detained on the US border with Mexico since last October, part of a trend that prompted Washington to ask for help from Central American nations.

Limited number of special cases

The president said that while some children may qualify for a status that would allow them to stay, the overwhelming majority would not.

"There may be some narrow circumstances in which there is a humanitarian or refugee status that a family might be eligible for," Obama said. "I think it's important to recognize that that would not necessarily accommodate a large number."

Obama also appealed for Republican members of Congress to act on a request for emergency spending to deal with the current influx.

The debate over immigration has become increasingly heated in the US, with Texas' Republican governor Rick Perry announcing the deployment of some 1,000 National Guard troops to his state's extensive border with Mexico. In California, a number of anti-immigration groups have taken to the streets with demands that illegal immigrants be sent home.

Since the US Senate last year passed an immigration reform bill, which included a path to legalization for some 11 million undocumented immigrants, the measure has run into problems in the Republican-controlled House of Representatives.

rc/jm (AFP, AP, Reuters)