Brazil, host of COP30, created 10 new indigenous territories, and the climate summit has been hit by protests in recent days.
This designation means that the culture and environment of these areas, including part of the Amazon, will be protected by Brazilian law, although this is not always respected.
The move follows similar moves by President Luiz Inacio Lula da Silva, whose government last year recognized indigenous ownership of 11 territories.
“Every indigenous territory in Brazil is a cause for celebration and a reason for us to feel happy,” Dinama Tuxu of the group Articulation of Indigenous Peoples of Brazil (APIB) told the BBC at COP30.
The latter measure will be formalized by presidential decree.
Mr Tuxu said the APIB wants more land to be legally recognised, giving groups the right to control what happens to the land within the boundaries.
“Indigenous peoples today protect 82% of the world's biodiversity. If you demarcate indigenous lands, you ensure that that area is protected,” he said.
“The traditional way of life of indigenous peoples protects the land and automatically guarantees the fight against global warming. Therefore, all humanity benefits from this,” he added.
Some indigenous peoples are attacked when they try to defend their land from herders or groups trying to cut down trees for agriculture.
A leader of a Guarani-Kaiowa community in southern Brazil was killed in an attack on Sunday, according to Survival International.
Vicente Fernandez Vilhalva, 36, was shot in the head as gunmen surrounded the village, according to witnesses who spoke to Survival International.
Thousands of people protested on Saturday outside the annual UN climate conference, with some carrying signs reading “Demarcation Now”.
And last week, demonstrators, some of them indigenous, carrying signs that read: “Our forests are not for sale,” stormed the summit and clashed with security guards.
Since then, security around the conference has noticeably increased, with more armed soldiers and police stationed at the entrance. Many indigenous groups are not accredited to enter.
But it is still the COP with the largest number of indigenous people.
“This makes me very happy. We worked for two years and now there are at least 900 people in the CC where they can negotiate and represent their communities,” APIB's Kleber Karipuna told BBC News.
On Monday, more than 200 human rights groups wrote to UN officials criticizing the heightened security measures, saying they “contribute to a growing global trend towards suppressing dissent, militarized responses to protests and the marginalization of those who defend the earth and the environment.”
Past recognition of Indigenous reserves Mining and logging are prohibited, and commercial agriculture is limited.in the areas they covered to prevent deforestation.
Expanding the total area considered indigenous territory could prevent up to 20% of additional deforestation and reduce carbon dioxide emissions by 26% by 2030, according to a study by the Articulation of Indigenous Peoples of Brazil, the Amazon Environmental Research Institute and the Indigenous Peoples' Committee on Climate Change.
Pages, Panaxo, Pancaya, Pancamba de Olivenza.
One area overlaps more than 78% with the Amazon National Park, part of a biodiverse rainforest that plays a critical role in regulating global climate and storing carbon.
The Brazilian government's announcement came on Indigenous Peoples' Day at the COP30 conference on Monday.
Until the leftist Lula returned to power, no new indigenous lands had been declared since 2018, he said.
Under his far-right predecessor Jair Bolsonaro, who promoted mining on indigenous lands, the protections he provided were often not respected.
Lula government already took action remove illegal miners from indigenous lands.
Indigenous lands currently cover 117.4 million hectares, roughly the size of Colombia, or about 13.8% of Brazil's territory.
Brazil is home to hundreds of indigenous groups, according to the country's census.
The Amazon rainforest is already under threat renewed surge in deforestation as efforts to overturn a key ban on its protection intensify. Dense and healthy forests help pull carbon out of the atmosphere.
The carbon released by burning fossil fuels has contributed to climate change.
Countries are meeting at COP30 to reach an agreement on how to try to limit the rise in global average temperatures to 1.5C above pre-industrial levels and keep it “well below” 2C.
The UN Intergovernmental Panel on Climate Change says a large body of scientific evidence shows warming of 2C or more will lead to severe impacts, including extreme heat, rising sea levels and threats to food security.
