The Obama administration’s emergency plan for dealing with a huge influx in illegal immigrant children from Central America is under the spotlight.
The first planeload to be deported arrived back in Honduras this week. But tens of thousands more have entered the US in recent months, fleeing poverty and violence.
The president wants Congress to approve 3.7 billion US dollars (2.73 billion euros) to provide care, speed up deportation hearings and increase border security.
The issue was highlighted by the high-profile arrest on Tuesday of a prominent activist and prize-winning journalist.
Jose Antonio Vargas, who campaigns for the rights of child migrants, has admitted being an undocumented immigrant himself.
He was later released, but pictures of his detention at a Texas airport sparked anger.
Trainloads of immigrants including unaccompanied children from Central America regularly arrive at the US border after travelling through Mexico.
US authorities have launched an advertising campaign to deter parents from sending their children north.
The ads highlight the dangers via a song called “La Bestia” or “The Beast”, as the train is known. The ballad has become one of the most popular on Central American radio.
The influx of children arriving from Mexico – more than 50,000 in the eight months to June – has prompted President Obama to call it a “humanitarian crisis”.
An opinion poll suggests more than half of Americans back the White House plan for dealing with it, although Obama himself receives poor personal ratings.