BRASILIA (Reuters) - Switzerland and the United States have donated $8.4 million to Brazil's Amazon Fund to help stop deforestation and preserve the world's largest tropical rainforest, the Brazilian National Development Bank (BNDES) that manages the fund said on Tuesday.

Switzerland contributed 5 million Swiss francs ($5.4 million) and the United States $3 million, the bank said in a statement.

The U.S. donation is part of a $500 million contribution over five years announced by President Joe Biden in April at a climate meeting where President Luiz Inacio Lula da Silva repeated Brazil's pledge to reach zero deforestation by 2030.

"These contributions reinforce the commitment and confidence of these countries in Brazil's environmental agenda and the Amazon Fund's actions in the region," the bank's social-environmental director Tereza Campello said.

The Amazon Fund was created in 2008 to raise donations to fight deforestation. Norway provided an initial $1 billion and Germany $68 million. More recently Britain and the European Union said they will contribute.

The fund supports the prevention, monitoring and combat of Amazon deforestation and fosters sustainable development. Since its creation, it has funded 102 projects with a total investment of 1.75 billion reais ($340 million), BNDES said.

($1 = 5.1550 reais)

(Reporting by Anthony Boadle; editing by Grant McCool)