French President Emmanuel Macron said on Sunday a deal to provide "technical and financial help" was close.
Leaders from the US, Japan, Germany, France, Italy, the UK and Canada continue their meeting in the seaside town of Biarritz on Monday.
It comes amid international tension over record fires burning in Brazil.
Critics have accused Brazil's President, Jair Bolsonaro, of "green lighting" the Amazon's destruction through anti-environmental rhetoric and a lack of action on deforestation violations.
UK Prime Minister Boris Johnson said Britain would provide £10m to protect the Amazon rainforest.
On Friday, facing mounting pressure from abroad, President Bolsonaro authorised the military to help tackle the blazes.