The custodians of the primal forests that stretch across eight Latin American countries said national leaders gathering in Los Angeles this week had to listen to them if they wanted to save the Amazon.
Indigenous leaders from across South America are in the United States for the Summit of the Americas, a semi-regular gathering of heads of state from the Western Hemisphere.
But, they say, many are not being allowed into the meetings where the land their people have called home for centuries is being discussed.
"In these important events, where there are governments in power, we should be hearing from indigenous people from different countries," said Domingo Peas, from the Achuar community in the Ecuadorian Amazon.
Peas, a member of the Confederation of Indigenous Nations of the Ecuadoran Amazon, traveled by boat, car, bus and plane over more than two days to get from his remote community of some 100 families to Los Angeles.
But when he arrived, he was told he would not be able to participate in the event, despite its having climate change as a major topic.
"Indigenous voices are not being heard at the summit, indigenous delegates are being denied entry," said Atossa Soltani, founder and president of the NGO Amazon Watch.
Not hearing what they have to say would be a huge mistake, she told AFP.
"Indigenous peoples not only have the solutions to our climate and biodiversity crisis, they are the original inhabitants.
"The reason we have these incredibly intact forests in Latin America, is because indigenous peoples for centuries and millennia have been taking care of the forests.
"They need to be at the table. They have something to teach the modern world."
The Summit of the Americas is being held in the United States for the first time since its inaugural edition in 1994.
The gathering, which was intended to showcase US President Joe Biden's engagement with the vast continent to the south, has floundered because a number of significant figures are not here.
Most conspicuously, Mexico's President Andres Manuel Lopez Obrador, whose co-operation is key if the Biden administration wants to get a handle on immigration, said he would stay away because leaders from Venezuela, Nicaragua and Cuba had not been invited.
Brazil's President Jair Bolsonaro, however, is expected to attend.
Soltani said Bolsonaro, whose country contains the lion's share of the Amazon needs to rein in the rampant commercial exploitation of the forest.
"The fate of the Amazon is in the hands of these world leaders who are gathering here this week. That is the fate of all of us. This is the future for our children, it's the future for life on this planet," she said.