Bogota: US President George W. Bush backed Colombia on Tuesday in an escalating Andean crisis as Venezuelan troops moved to the border and Colombia accused President Hugo Chavez of genocide for supporting rebels.

Chavez, who calls Bush "Mr. Danger" and has threatened to stop selling oil to the United States if it attacks, has warned war could break out in a dispute that erupted when Colombian forces bombed inside another neighbor, Ecuador, to kill a leading leftist rebel.

Bush weighed in on the crisis for the first time since Saturday's raid, accusing Chavez of provocative maneuvers and warning he opposed any act of aggression in the region.

Bush told reporters about a phone call with President Alvaro Uribe in which he said "that America would continue to stand with Colombia."

The conservative Uribe, whose government receives billions of dollars in US military aid, threatened to take Chavez to international court for backing genocide by supporting Marxist FARC rebels in Colombia.

"We are not warmongers, but we are not weak," said Uribe, who also accuses Chavez's leftist ally in Ecuador, President Rafael Correa, of supporting the rebels of the Revolutionary Armed Forces of Colombia (FARC).

"We cannot allow terrorists who seek refuge in other countries to spill the blood of our countrymen."

Chavez calls Uribe a pawn in a US plot to invade his Opec nation, the No. 4 oil supplier to the United States.

Venezuelan media showed on Tuesday the first noticeable troop movements in buses and trucks two days after Chavez ordered tanks and forces to the border.

Caracas also began restricting Colombian commercial traffic on points along the frontier, witnesses and businesses in Venezuela said. The move threatened to disrupt the $6 billion per year in trade between the two countries,

The crisis reflected a sharp political divide in South America, where Uribe is opposed by leftists led by Chavez who fiercely reject what they brand as US "imperialism."
Latin American countries scrambled to defuse the crisis, which they worried threatened regional stability.

Despite the three leaders' brinkmanship and the risk of military missteps, political analysts said a conflict was unlikely on borders that stretch from parched desert through Andean mountains and jungles to the Pacific Ocean.