Brazil's military has stepped up rescue and supply operations in areas hit by floods and landslides that have killed at least 655 people.
Heavy rains last week sent an avalanche of mud, water and rocks through towns and villages.
The death toll has been rising steadily as rescuers find more bodies in the mudslides and wreckage of buildings.
Helicopters have reached residents who had been cut off from help for five days.
The Air Force says clearer weather conditions have allowed the aircraft to more safely navigate the craggy terrain in the area north of Rio de Janeiro city.
Hundreds of people are believed to still be in areas at risk of fresh mudslides.
In the capital Brasilia, the government sought to fend off criticism over its response by announcing that it would implement a national alert system to warn people in risky areas of approaching natural disasters.
The announcement came after the Estado de Sao Paulo newspaper reported that Brazil had failed to meet a series of recommendations on improving disaster preparedness made by the United Nations in 2005.