LOS ANGELES, USA (AFP) — Latinos yesterday hailed US President Barack Obama's announcement on letting young law-abiding illegal immigrants stay in the US, while a notoriously hardline Arizona sheriff blasted the move.

A rally in downtown Los Angeles which had been planned to lobby for the Dream Act turned into a celebration, while mayor Antonio Villaraigosa hailed the move as reaffirming America's image as a country of immigrants.

"I couldn't be prouder of our president for doing what was right, for doing what I believe confirms and reaffirms once again that America is an embracing place," he told CNN.

As dozens of pro-Dream Act campaigners chanted "We are the dreamers" in downtown LA, Angelica Salas, head of the Coalition for Humane Immigrant Rights of Los Angeles, said: "We knew you could, Mr President.

"Americans will look back on this day with pride and joy when they allowed these young people to fully contribute to the growth, prosperity, and strength of our great nation.

"If what we heard today is exactly what happens, it was about time. Si se puede!" (Yes We Can, Obama's 2008 campaign slogan) she added.

In neighboring Arizona, which has among the highest population of Latinos from south of the border in the US, the White House announcement was also hailed.

"This is a big step for our youth, for those young people who have the courage to fight for their dreams," said Petra Falcon, head of Promise Arizona (PAZ).

But hardline Arizona sheriff Joe Arpaio said the move was politically motivated, ahead of November elections.

"I'm not surprised this is happening... I feel this is politics to get the Latino vote. The decision will be coming out Monday. Why can't they wait? Why is he doing this now? We all know the answer.

"Why is the president right now and the homeland security secretary coming up with this policy. It's going to be hard to administer any way. I can go into many reasons to make this policy work. I'm not for it.

"It's a step towards amnesty," he added.