The G7’s pledge of $20m (£16m) to douse the fires in the Amazon has been dismissed as “chump change” by environmental campaigners, as concerns grow about political cooperation on deforestation and other climate issues.

The summit host, the French president, Emmanuel Macron, told reporters he would try to deal with the long-term causes by creating an international alliance to save the rainforest, with details of a reforestation programme to be unveiled at next month’s UN climate meeting in New York.

But the US president, Donald Trump, skipped the summit session aimed at finding solutions to global heating through tree planting and shifting from fossil fuels to wind energy. In a press conference after the summit, he was dismissive of efforts to change direction.

“I feel the US has tremendous wealth … I’m not going to lose that wealth on dreams, on windmills – which, frankly, aren’t working too well,” he said. “I think I know more about the environment than most.”

The most concrete outcome of the three-day summit of major industrialised democracies in Biarritz was the $20m that leaders promised to make immediately available to Amazonian nations such as Brazil and Bolivia, primarily for more firefighting planes.

The assistance plan, announced by the French and Chilean presidents on Monday, would involve a programme of reforestation, to be unveiled at the UN general assembly meeting next month.

“We must respond to the call of the forest, which is burning today in the Amazon,” said Macron.

Environmental groups said the emergency fire aid was insufficient and failed to address the trade and consumption drivers of deforestation. “The offer of $20m is chump change, especially as the crisis in the Amazon is directly linked to overconsumption of meat and dairy in the UK and other G7 countries,” said Richard George, the head of forests for Greenpeace UK. “The UK has plenty of leverage to stop the destruction of the Amazon by suspending trade talks with Brazil until its full protection is guaranteed. Any post-Brexit trade deals must prioritise the environment and human rights.”

But there was also appreciation that several G7 leaders, including the UK’s Boris Johnson, had expressed concerns about the Amazon. Macron said he had had long and in-depth talks with Trump on the Amazon fires and that Trump “shares our objectives” and was “fully engaged” in the joint effort to help put out the fires and reforest.

“It’s good to see the fate of this vital forest on the global agenda, as well as new commitments of funding, especially from the UK. But protecting this incredible forest, and the future of the planet, will take bolder action,” WWF said. “That will require us to stop importing commodities that drive deforestation.”

Conservation groups in Brazil said the sums were tiny compared with the hundreds of millions of dollars Brazil was losing in donations from Norway and Germany as a result of President Jair Bolsonaro’s policies in the Amazon.

“The amount offered [by the G7] is far from significant, but resources do not seem to be a problem for the Brazilian government,” said Adriana Ramos, the policy director of Brazilian NGO Instituto Socioambiental. “This money that has been blocked could be made available with a stroke of the pen by the president if he really had any political interest in combating deforestation and fires in this country.”

Forest fires in Altamira, Para State, Brazil on Friday. Photograph: Victor Moriyama/AFP/Getty Images

Environmental experts said Bolsonaro’s policies have fuelled accelerating deforestation and contributed to the intensity of the wildfires. France and Ireland have threatened to block an EU trade deal with Brazil and three other Latin American countries if Bolsonaro does not change course.

Macron’s criticism sparked an angry response from Bolsonaro, who accused him on Monday of treating Brazil like “a colony or no man’s land”. But the international pressure has prompted the president to deploy two C-130 Hercules aircraft to tackle the fires.

The reforestation plan would require the consent of Bolsonaro and local communities. The Chilean president, Sebastián Piñera, a Bolsonaro ally on the political right, said he was in constant touch with the Brazilian president and that the two leaders had spoken as recently as Sunday. He said he was confident he would be able to convince him about the need for reforestation of the Amazon.

“I will discuss that with him. But I think that it is absolutely necessary. And I tend to think that he will agree,” Piñera told the Guardian.

“In the last 20 years, almost 10% of the use of the surface of the Amazon has been destroyed. We can recover that. It will take time. It will take money. It will take effort but we can do it,” said Piñera.

Piñera suggested Macron and other world leaders had set about trying to make Bolsonaro change course in the wrong way, criticising him rather than cooperating with him.

“The Amazon is in South America, and the countries there have sovereignty over that territory they want to protect,” Piñera said. “At the same time the Amazon is part of the health of the whole planet. And therefore it is reasonable that everybody is concerned about that. We have to find a compromise between those two.”

Piñera was speaking before news came that Bolsonaro had endorsed an insulting comment on Facebook about Macron’s wife, Brigitte.

Under the umbrella of the G7 summit, a coalition of more than 50 indigenous groups and environmental organisations issued their own statement, adding to the political pressure. With the support of Macron, they directly blamed Bolsonaro for accelerating the clearance of the rainforest by “systematically dismantling” environmental protection agencies, halting the demarcation of indigenous land, and verbally attacking anyone who opposed forest clearance.

The declaration urged the G7 to strengthen import restrictions on beef, soy, minerals and other products that originate from areas affected by deforestation, enhance due diligence for investments in the Amazon to ensure they do not violate human rights and environmental controls, and to support Brazil to achieve the Paris climate targets.