The crisis gripping South America took a step closer to open conflict on Wednesday with Venezuela saying 10 batallions were now on the Colombian border, and Ecuador warning "ultimate consequences" could ensue.
The developments increased pressure on frantic diplomatic efforts to resolve the dispute, which has raised the spectre of OPEC members Venezuela and Ecuador, led by leftists, going to war against conservative US ally Colombia.
Ecuadoran President Rafael Correa, in Brazil to drum up regional support for his country, warned that Colombia must be condemned internationally for its cross-border strike inside Ecuador on the weekend.
"Otherwise we will have to defend ourselves by our own means. I insist on this: Ecuador is ready to go to the ultimate consequences," he told reporters.
Venezuela, which has given full backing to Ecuador, confirmed that 10 of its army batallions, around 6,000 men had been sent to the frontier and were 90 per cent in place.
The mobilisation was "not against the people of Colombia, but rather against the expansionist designs of the Empire," Venezuelan Defence Minister Gustavo Rangel said, referring to the United States, which has thrown its weight behind its ally Colombia.
The trigger of the crisis was an air and land raid by Colombia inside Ecuador on Saturday to kill a leader of the Revolutionary Armed Forces of Colombia (FARC), the Marxist guerrilla group it has been fighting for four decades.
Ecuador and Venezuela responded by ordering troops to their borders with Colombia and cutting off diplomatic ties.
US President George W Bush hailed Colombian President Alvaro Uribe for going after the FARC and blamed the heightened tensions on "provocative manoeuvres" by longtime foe, Venezuelan leader Hugo Chavez.
Correa, who was to talk with Brazilian President Luis Inacio Lula da Silva, said the US backing of Colombia was unsurprising, and described Uribe as Washington's "unconditional puppet".
He said: "There has been an agression. The agressor has to apologize and the international community has to condemn it."
Correa said his country saw no negotiated solution because "there is nothing to negotiate".