Joe Biden became the first sitting US president to visit the Amazon rainforest on Sunday, flagging the dangers of global warming often dismissed by President-elect Donald Trump, who has vowed to scrap measures to fight climate change.

Biden flew from Lima, Peru, to Manaus, Brazil, the largest city in the Amazon, to meet with local leaders working to preserve the rainforest.

Dressed casually in a blue shirt and pants, the 81-year-old chatted on the tarmac with local dignitaries before boarding a helicopter to fly over the rainforest.

During the helicopter tour, Biden saw severe erosion, ships grounded in one of the Amazon River’s main tributaries and fire damage. He also passed over a wildlife refuge for endangered species of monkeys and birds and the expansive waters where the Negro River tributary flows into the Amazon. He was joined by Carlos Nobre, a Nobel Prize-winning scientist and expert on how climate change is harming the Amazon.

Biden met indigenous leaders - introducing his daughter and granddaughter - and visited a museum at the gateway to the Amazon where indigenous women shook maracas as part of a welcoming ceremony. He then signed a US proclamation designating November 17 as International Conservation Day.

The Amazon is home to indigenous communities and 10 per cent of Earth’s biodiversity. About two-thirds of the Amazon lies within Brazil. Scientists say its devastation poses a catastrophic threat to the planet.

During brief remarks from the forest, Biden sought to highlight his commitment to the preservation of the region. He said the US was on track to reach US$11 billion in spending on international climate financing in 2024, a six-fold increase from when he started his term.

“The fight to protect our planet is literally a fight for humanity,” he said.

Biden is making the Amazon visit as part of a six-day trip to South America, the first to the continent of his presidency. He traveled from Lima, Peru, where he took part in the annual Asia-Pacific Economic Cooperation summit and met with President Xi Jinping. (Agencies)