They plan to urge Washington to extend expiring trade benefits designed to help counter cocaine production in the South American region.
The presidents of Colombia, Ecuador, Peru and Bolivia sought the extension of US trade benefits for Ecuador and Bolivia on Tuesday.
The agreement was aimed at soothing friction caused by the decision of Hugo Chavez, the Venezuelan president, to split from their five-nation bloc in protest over US free trade deals.
The Andean leaders meeting in Quito, Ecuador, agreed that Alvaro Uribe, the Colombian president, would ask George Bush, the US president, to extend reduced trade tariffs for Ecuador and Bolivia as a reward for efforts to eradicate crops such as the coca leaf used to make illegal drugs.
The reduced tariff accord is due to expire in December. Uribe is expected to make the request during a visit to Washington on Wednesday.
Jorge Humberto Botero, the Colombian trade minister, said: "All countries would benefit from an extension.
"The Andean leaders asked that President Uribe take a message from the Andean countries during his meeting tomorrow with President Bush."
Andean leaders also want a consensus on how the bloc can negotiate for a free trade agreement with the European Union. Trade among the five Andean nations reached $9 billion last year.
Chavez, who says he is trying to free Venezuela and Latin America from US imperialism, pulled out of the Andean Community in April, accusing Colombia and Peru of scuttling the group by concluding trade deals with the United States.
Chavez wants to free Latin
America from US imperialism
Allied with Cuba, Chavez has promoted a socialist revolution as a counterweight to US-backed economic policies and joined forces with Bolivia in a push for more state control over energy resources.
Chavez' stance contrasts with that of leaders in Brazil and Chile who try to balance their left-wing ideology with ties with Washington.
US officials say Chavez is destabilising the region by using Venezuela's oil wealth to influence the affairs of neighbouring nations, a charge he dismisses.
Evo Morales, Bolivia's first indigenous president, had sided with Venezuela and Cuba in calling for an alternative. He has not entered free trade talks, but the former coca leaf farmer agreed to a united Andean front.
"We need unity fundamentally to face more powerful foreign forces, to face the United States and negotiate on better terms, to have dialogue on better terms"
president of Bolivia
"We need unity fundamentally to face more powerful foreign forces, to face the United States and negotiate on better terms, to have dialogue on better terms," he said.
Morales met later with Ecuadorean Indian leaders who led protests earlier this year against free trade accords. Waving Bolivian and rainbow-hued indigenous flags, several hundred supporters chanted slogans against US trade deals and a US military base in Ecuador.
Peru signed a US free trade accord in April and Colombia completed negotiations in February.
Ecuador's free trade talks are frozen and face protests from indigenous leaders who fear a deal will threaten their livelihoods.