Brazil has launched an international fund to protect the Amazon rainforest and help combat climate change.
The fund will promote alternatives to forest-clearing for people living in the Amazon, and support conservation and sustainable development.
Officials will seek donations from abroad and aim to raise $28.5bn by 2021.
But a government minister said Brazil would not accept foreign interference in its Amazon policy.
The environmental group Greenpeace says it is the first time Brazil had accepted a link between global warming and preserving the rainforest.
Importance of the rainforest
Speaking at the launch in Rio de Janeiro, the Brazilian President Luis Inacio Lula da Silva said Brazil was aware of how much the Amazon meant to the wider world.
"It's better for the country's image to do things right, so we can walk in international forums with our heads held high," he says.
But the Brazilian leader also insisted that the Amazon's preservation was Brazil's responsibility.
"We ... want the sovereignty that we hold over Amazonian territory and the decisions that are made in this region to be respected," he says.
Roberto Mangabeira Unger, minister for strategic affairs, put the point more forcefully:
"The fund is a vehicle by which foreign governments can help support our initiatives without exerting any influence over our national policy.
"We are not going to trade sovereignty for money."
Greenpeace in Brazil said that the country was accepting the link between global warming and preserving the forest for the first time.
"For a long time, Brazil was violently opposed to this, insisting fossil fuel was to blame," said Sergio Leitao, director of public policies for Greenpeace Brasil.
"That's true, historically speaking, but today forests play an important role."