British Prime Minister Boris Johnson on Monday pledged £10 million ($12.3 million) to help restore the Amazon rainforest which has been ravaged by fires, sparking a wave of global concern.

The money would be made available immediately to help restore the habitat, including areas that have been hit by the fires, the British government said in a statement released at the G7 summit in the French resort of Biarritz.

The pledge came after French President Emmanuel Macron, who is hosting the summit, said Sunday that world leaders had agreed to help the countries affected by the wildfires as soon as possible.

"In a week where we have all watched, horrified, as the Amazon rainforest burns before our eyes, we cannot escape the reality of the damage we are inflicting on the natural world," Johnson said in a statement.

Although about 60 per cent of the Amazon is in Brazil, the vast forest also takes in parts Bolivia, Colombia, Ecuador, French Guiana, Guyana, Peru, Suriname and Venezuela.

Macron's bid to put the Amazon crisis high on the agenda at the G7 angered Brazil's far-right leader Jair Bolsonaro, who lashed out over what he sees as outside interference, denouncing the French leader's "colonialist mentality".

Johnson also said it was essential for the international community to tackle the key environmental issues of climate change and biodiversity loss.

"These are two sides of the same coin -- it is impossible to solve one challenge without fixing the other," he said.

"We cannot stop climate change without protecting the natural environment and we can't restore global nature without tackling climate change."

He confirmed Britain hopes to host the 2020 UN Climate Change Conference, known as COP26, which experts see as a critical moment in testing the commitments of governments to fight against global warming.

Johnson said the conference "will have as a major focus the solutions to climate change that can be found in nature -- such as reforestation".