RIO DE JANEIRO (Reuters) -A majority of Brazilians believe President Luiz Inacio Lula da Silva should ban oil exploration off the coast of the Amazon rainforest, a sensitive ecosystem that is also Brazil's most promising oil frontier, according to a Datafolha survey commissioned by Eko, a corporate accountability group.

The survey, conducted in early September, comes as Brazil prepares to welcome world leaders in the Amazonian city of Belem for this year's United Nations climate summit, COP30. As host, Brazil is positioned to urge the international community to accelerate the shift away from fossil fuels.

The survey found that 61% of respondents oppose oil extraction in the Foz do Amazonas basin, an area near the mouth of the Amazon River, where state-controlled Petrobras is seeking environmental approval to drill an exploratory well. Opposition was highest among Brazilians aged 16-24, with 73% against the project.

Petrobras, which has spent 180 million reais ($33 million) keeping a drill ship on standby, aims to explore deep waters off the state of Amapa for oil reserves to establish a new exploratory frontier. The survey did not mention Petrobras, which has faced resistance from civil society groups and some government officials.

Despite positioning himself as a global advocate for the struggle to curb climate change, Lula has defended Brazil's right to assess the region's oil potential.

"The coming months will be decisive for Lula's legacy," Eko campaign coordinator Vanessa Lemos said in a statement. "The majority of Brazilian voters want him to protect nature and the climate."

Ibama, Brazil's federal environmental agency, approved an emergency simulation for the drilling site in September but requested adjustments before granting final licensing. Petrobras is awaiting a response.

Despite challenges, interest in the basin remains high. In June, Petrobras, ExxonMobil, Chevron, and CNPC secured 19 of 47 oil and gas exploration blocks offered in the region.

The survey highlighted broader support for environmental protection, with 77% agreeing with Lula's goal to end illegal deforestation by 2030, though only 17% believed the target was achievable. Additionally, 60% of respondents reported negative impacts from climate change, while 81% said the government should do more to protect marginalized communities.

(Reporting by Marta Nogueira; editing by Roberto Samora, Manuela Andreoni and Aurora Ellis)

Majority of Brazilians oppose oil drilling near the Amazon coast, poll shows