Brazil's environment minister says the country needs $10bn (£7.2bn) a year in foreign aid in order to reach zero emissions by 2050.
The move would mean that Brazil could achieve the symbolic figure 10 years earlier than currently planned.
It comes ahead of US President Joe Biden's climate summit next week.
Brazil's environmental policies have brought international condemnation since President Jair Bolsonaro took office two years ago.
He has encouraged agriculture and mining activities in the Amazon, the world's largest rainforest.
Environment Minister Ricardo Salles said $1bn would be used to reach zero illegal deforestation in the Amazon by 2030.
He added that a third of the money would be used to recruit more environmental agents, potentially from the national military police. The remainder would be used to invest in sustainable development of the Amazon, he told Reuters news agency.
Mr Salles said he does not expect a deal to be made before next week's virtual summit.
His call for foreign aid comes as Mr Bolsonaro's government is attempting to negotiate a deal with the US in which it would receive financial aid in return for protecting the Amazon.
The move has been criticised by environmentalists and indigenous groups who say they haven't been consulted on the plans.
A report by Brazil's space agency (Inpe) released in 2020, said that deforestation of the Amazon had surged to its highest level in 12 years. The Amazon is home to about three million species of plants and animals, and one million indigenous people.
Mr Bolsonaro has previously clashed with Inpe over its deforestation data, accusing it of smearing Brazil's reputation.
Vice-President Hamílton Mourão said Brazil has a set goal to reduce illegal deforestation by 15-20% per year in order to eliminate it by 2030. He said that the target was mentioned in a letter sent by Mr Bolsonaro to Mr Biden earlier this week.