The G7 countries have agreed to an immediate $20m (£16m) aid package to help Amazon countries fight wildfires and launch a longer-term global initiative to protect the rainforest.

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 Emmanuel Macron of France, after a meeting of the G7 major industrialised democracies on the climate emergency near the end of a three-day summit in Biarritz.

However, it was unclear on Monday evening whether the Brazilian president, Jair Bolsonaro, would cooperate with the plan. He sent out a string of tweets within minutes of the G7 announcement, criticising Macron for treating Brazil as if was “a colony or a no-man’s land”.

Macron conceded that Donald Trump had not attended the G7 session on climate change, biodiversity and the oceans, but he said that “his team was there”, and that the US supported the initiative.

Facebook Twitter Pinterest Chile’s President Sebastian Pinera (left) speak during a joint press conference focused on climate issues in Biarritz with President Emmanuel Macron of France. Photograph: François Mori/AFP/Getty Images

Environmental experts say the policies of the Brazilian president, Jair Bolsonaro, reducing environmental protections, have fuelled accelerating deforestation and contributed to the intensity of the wildfires. France and Ireland have threatened to block a 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 of colonialism. Under international pressure, however, Bolsonaro finally deployed two C-130 Hercules aircraft on Sunday to douse the fires.

The reforestation plan, to be discussed at the UN next year, 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 the two leaders spoke 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 an interview at the summit.

“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,” the Chilean president said.

Piñera suggested that 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. He argued that one of the achievements of the Biarritz summit was to establish a more collaborative process that respected the sovereignty of Amazonian countries.

“At the beginning, there was a kind of collision between the president of France or the president of Brazil. Now they are working together,” Piñera said. x

“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. And that was the problem between Macron and Bolsonaro at the beginning, but it has already been solved because now both the G7 and the Amazon countries, with the collaboration of Chile are pushing in the same direction.”

The Chilean president was speaking before Bolsonaro unleashed his tweetstorm against Macron.

“We can’t accept that a president – Macron – fires off improper and gratuitous attacks on Amazonia,” Bolsonaro wrote. “Nor that he hides his intentions behind the idea of an ‘alliance’ of G7 countries to ‘save’ Amazonia, as if we were a colony or no man’s land.”

Facebook Twitter Pinterest Jair Bolsonaro, president of Brazil. Photograph: Eraldo Peres/AP

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 on the Brazilian government.

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 opposes forest clearance.

“Problems of deforestation and burning in the Amazon have a long history; however, the worsening of this situation in 2019 is a direct result of the behaviour of the government of President Jair Bolsonaro,” said the statement, which was read out by leaders of the Raoni indigenous community. “President Bolsonaro has encouraged the criminalisation of social movements and NGOs, reaching the absurdity of blaming them for increased burning in the Amazon.”

Facebook Twitter Pinterest Activists hold up a banner of Jair Bolsonaro as they gather in front of the Brazilian embassy during a demonstration in Brussels, Belgium. Photograph: Thierry Monasse/Getty Images

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.