Venezuelan President Hugo Chavez lost an ally with the ouster on Sunday of the Honduran President, but the steadfast US antagonist is rattling sabres and rallying his leftist political bloc during a regional test for the White House.

Honduran troops overthrew President Manuel Zelaya, a member of Mr Chavez's ALBA trade bloc, after he sought to amend the constitution to extend his time in office - just as Mr Chavez and leftist allies in Ecuador and Bolivia did before him.

Mr Chavez, a foe of US trade and foreign policy in Latin America, has used Venezuela's oil wealth to become a flag-bearer for leftist sentiment in the region, especially during the administration of President George W. Bush.

Within hours of Mr Zelaya's ouster, Mr Chavez planned an emergency summit in Nicaragua of ALBA allies and warned that he would respond militarily if Honduran forces kidnap or harm his diplomats in the Central American country.

Mr Chavez, who himself had been briefly ousted in a 2002 coup he blamed on Mr Bush, also said he wanted a probe into any role the CIA may have played in Mr Zelaya's toppling.

ALBA "will present this as proof of a conspiracy against their movement," said Eduardo Gamarra, a Florida-based professor of Latin American studies. "The US cannot afford to be accused of being involved in this in any way."

President Barack Obama expressed concern over Mr Zelaya's ouster, while US officials dismissed claims the country supported the coup.

But ALBA, whose members include Cuba and Nicaragua, has few tools as a group to pressure for action involving Honduras beyond diplomatic measures and tough statements.

For years, Washington portrayed Mr Chavez as a threat to the region. But Mr Obama offered him a new start, and Mr Chavez has generally toned down his attacks on the "US empire" since.

Mr Chavez, a loyal partner of communist-ruled Cuba, has also tried to woo allies in international forums like the UN and the Organisation of American States or OAS.

But his anti-Washington rhetoric cost his foreign policy initiatives in the past. He lost out on a UN Security Council seat after blasting Bush as a devil.

Despite Mr Chavez's entreaties, some in the region are looking for friendlier US ties and ways to ward off the global economic crisis.