WASHINGTON—President Joe Biden’s climate summit of 40 world leaders this week will be Brazilian President Jair Bolsonaro’s “last chance” to restore Washington’s confidence in Brazil’s commitment to taking action to fight climate change, the U.S. ambassador to Brazil has warned.

But pressure from Brazilian civil society groups has complicated the situation for Bolsonaro, and paved the way for one of its neighbors—Colombia—to step in as Latin America’s primary leader on climate.

A bilateral agreement Brazilian officials had hoped could be announced during the summit has stalled after nearly 200 Brazilian advocacy groups sent a joint letter to Biden earlier this month, calling on him to “choose between being true to his speech and lending political prestige and money to Bolsonaro.” They warned that negotiating with the Brazilian president “is not the same as helping Brazil solve its problems.”

Meanwhile, Biden’s top aide for Latin America, Juan Gonzalez, met with Colombian President Iván Duque last week to discuss the country’s regional climate leadership. Gonzalez’s South American tour did not include a stop in Brazil.

On Friday, 15 Senate Democrats joined the effort to rebuff the Brazilian president by writing to Biden that cooperation between the two nations “can only be possible if the Bolsonaro administration begins to take Brazil’s climate commitments seriously.” They added that U.S. aid to Brazil should be conditioned “on the Brazilian government making significant, sustainable progress.”

The efforts by the Brazilian groups are “breaking through to policymakers in the U.S.,” said Jessica Carey-Webb, a Latin America campaign advocate at the Natural Resources Defense Council. “The Biden administration is cognizant of the issues in dealing with Bolsonaro and Brazil … They are trying to be cautious and do their due diligence in terms of really thinking through what a potential deal could look like.”

Brazilian Environment Minister Ricardo Salles announced on Friday that “there is not and was never the objective of negotiating some kind of deal to deliver on April 22.” Last week, White House Spokeswoman Jen Psaki had already stated that the forum was not intended as a platform for bilateral negotiations or deals, but for nations to lay out plans for increasing their ambition.

Bolsonaro and his American counterpart have clashed over climate policy at least since last year’s elections, when President Joe Biden expressed outrage that “rainforests of Brazil are being torn down.” Bolsonaro, closely allied with the Trump administration, called Biden’s declaration “disastrous and unnecessary.”

More than half a year later, in a Wednesday letter to Biden, Bolsonaro expressed his “commitment to eliminate illegal deforestation in Brazil by 2030” and asked for the U.S. president’s “personal engagement” to address the issue.

He also noted that to address the problem, Brazil will require “massive resources,” including financial support from “the United States government, the private sector and the American civil society.” (After Biden said during a debate last September that he would “make sure” the international community raised $20 billion for the Brazilian Amazon, Bolsonaro said he did not take “bribes.”)

Later last week, Salles announced Brazil will need $10 billion a year in aid to reach net-zero carbon emissions by 2050, a few days after announcing Brazil had requested $1 billion upfront from Western nations to protect the Amazon.

Reacting to Bolsonaro’s letter, Biden’s Special Envoy for Climate John Kerry expressed on Twitter that “President Bolsonaro’s recommitment to eliminating illegal deforestation is important. We look forward to immediate actions and engagement with indigenous populations and civil society so this announcement can deliver tangible results.”

Whatever relationship emerges, the Biden administration might already have its eyes on Colombia to lead Latin America’s fight against climate change.

Last week, in his first official trip to South America, González visited Bogotá to discuss, among other topics, the country’s “regional climate leadership.” After the meeting, Colombian Foreign Affairs Minister Claudia Blum indicated that climate policy was a “big part” of the meeting, in which they “explored the decisions taken by Colombia to tackle climate change and the American interests in this global agenda.” At another event last week, Andrew Griffin, a State Department deputy director, saluted Colombia for its climate leadership.

“The United States recognizes Colombia’s leadership in the region on tackling climate change, including efforts to aggressively reduce greenhouse gas emissions, conserve the Amazon, tackle deforestation and other illicit activities, and further develop its renewable energy market,” a State Department official said. “Those efforts include Colombia’s announcement of an ambitious update to its nationally determined contribution and its detailed implementation plan” for the Paris climate agreement on climate change.

In its environmental action forecast for 2021, published in December, the NRDC listed Colombia as a “climate leader” and Brazil as a “climate laggard.” While Colombia’s nationally determined contributions to the Paris Agreement include a vow to reduce greenhouse gas emissions by half by 2030 and to plant 180 million trees in the next year, Brazil became one of the only participant countries to decrease the level of ambition of its goals. The country has increased the amount of carbon emissions it is permitting and has allowed for higher levels of Amazon deforestation.

Although both countries form part of the Amazon basin, almost two-thirds of the rainforest’s territory is located in Brazil. Under Bolsonaro, deforestation has skyrocketed, reaching a 12-year peak.

About a possible shift in climate leadership in Latin America, the State Department official said that “tackling the climate crisis requires global partnerships with big impacts,” and added that both “Brazil and Colombia will be key partners in finding and implementing the solutions to this crisis.”

Meanwhile, the Bolsonaro administration said that, together, Brazil and Colombia “contribute to the sustainable development of the Amazon,” and added that “assistance from the United States would enable Brazil to ramp up these efforts and further its ambition to preserve the Amazon.”

“The Brazilian government welcomes the engagement of all Amazonian countries in efforts to preserve the forest and contribute to the social development of the region,” the Brazilian Embassy in Washington said in a statement. “The preservation of the Amazon is a common challenge that can only be tackled through the cooperation of all the countries in the region.”

The Brazilian Embassy confirmed both Bolsonaro and Salles will attend the summit. The Colombian president will also participate.

Augusta Saraiva is a Washington-based Brazilian journalist covering U.S. foreign policy, geopolitics and geoeconomics. Her work has been published across the Americas—in the U.S., Brazil, Argentina, and Colombia—and has appeared in publications such as Foreign Policy, Voice of America and USA TODAY. She is a graduate student in political journalism at Northwestern University.