Brazilian regulator upholds block of Amazon oil drilling despite president's doubts

Brazil's environmental agency rejected Petrobras's request to drill offshore of the Amazon River.
Petrobras wanted to drill near biodiverse mangroves and coral reefs, raising environmental concerns.
Brazil's president expressed doubts the project would harm the environment but regulator is unlikely to reverse decision.
Petrobras plans to appeal but regulator's technical team is unlikely to approve without project changes.
The decision highlights debate over Brazil's energy future and protecting the Amazon rainforest.