A record number of blazes are ravaging the rainforest, many of them thought to have been started deliberately in Brazil, drawing international concern because of the Amazon's importance to the global environment.

"We will straightaway offer Amazonian countries that signal to us their needs, financial support of at least up to 20 million euros ($22 million)," said Macron, who is locked in a war of words with Brazil's President Jair Bolsonaro.

Macron last week accused Bolsonaro of lying about his environmental commitments.

The Brazilian president hit back, accusing Western countries of interfering in his country's affairs and mocking the looks of the French leader's 66-year-old wife on Facebook.

"It's sad, it's sad first of all for him and for Brazilians," Macron said in response on Monday.

Standing alongside Chilean President Sebastián Piñera, who was invited to join the wealthy-nation leaders in the French seaside resort of Biarritz, Macron said G7 countries were ready to provide concrete support to the region.

"France will do so with military support in the coming hours," he said, without giving further details.

The plan decided at the G7 will be implemented in two stages, said Piñera. "Countries urgently need fire fighters and specialised water bombers. This will be the first step that will be implemented immediately.

"The second phase is to protect these forests, protect the biodiversity they contain and reforest this region of the world," he added.

Macron added that the G7, which comprises the United States, France, Germany, Japan, Italy, Britain and Canada, would draw up an initiative for the Amazon that will be launched at next month's UN General Assembly in New York.

Bolsonaro, a right-wing leader who wants to open the Amazon to more farming and mining, said on Twitter that Macron's initiative treated Brazil like "a colony or no-man's land" and an attack on its sovereignty.

US President Donald Trump was absent from the talks on climate change and biodiversity at a G7 session on Monday, and Macron said he had been busy holding bilateral meetings.  "He wasn't in the room, but his team was," Macron said. "You shouldn't read anything into the American president's absence... The US are with us on biodiversity and on the Amazon initiative."