(BBC) -Mexican President Felipe Calderon has pledged the full support of his government to help more than a million people hit by floods in Tabasco state.
In a visit to the state capital, Villahermosa, Mr Calderon said the entire air force was involved in shifting supplies to the region.
Rescue workers are trying to help thousands of people trapped in their homes by the floodwaters.
Some 70% of the state is under water in the worst floods for 50 years.
On Friday, the floodwaters were still rising and more rain was forecast for the weekend.
Rescue workers are using helicopters and boats to move people stranded on rooftops or pockets of high land.
The state governor has urged anyone who owns a boat to help the rescue efforts, alongside army and navy crews.
President Calderon called on private airlines to help with the relief efforts as all roads in and out of the state are cut off by the floodwaters.
After flying over the state, Mr Calderon described the flooding as "not just the worst natural catastrophe in the state's history but, I would venture to say, one of the worst in the country's recent history".
He said soldiers and federal police had been called out to prevent looting and urged residents of Tabasco to remain calm.
Once the critical stage was over, he said, "we are going to reconstruct Tabasco whatever it takes".
The floods were triggered by storms that crippled Mexico's oil industry.