The death toll of Tropical Storms Manuel and Ingrid in Mexico now stands at 110, the interior minister says.
Another 68 are still missing, believed dead, after a landslide destroyed the village of La Pintada in western Guerrero state.
President Enrique Pena Nieto asked Congress to increase the federal budget in light of the emergency.
Officials are still trying to evaluate the total extent of the damage.
“We are confronting rainfall that has practically been the most extensive in the history of the entire national territory,” President Enrique Pena Nieto said on Sunday.
“Today we can already anticipate that due to the damages that we have seen, our [emergency] funds are insufficient.”
Interior Minister Miguel Angel Osorio Chong said work was under way to establish which areas were worst affected by Tropical Storm Manuel which hit Mexico’s western coast, and Ingrid, which made landfall on its eastern coast last week.
Twenty-four out of Mexico’s 31 states have been affected by the twin storms.
“There’s no point in the government offering us kind words and nothing else,” Alicia Sanchez told the Associated Press news agency.
“They’ve made us promises but I don’t think they’ll keep them,” the Acapulco resident said.
Acapulco’s international airport re-opened for commercial flights on Sunday, a week after it had to close due to power cuts and flooding.
Some 20,000 people are still living in shelters in the surrounding state of Guerrero.
Rescue workers continue to search the rubble and mud for bodies of those buried in a landslide in La Pintada, where some 40 homes were swept away by mud from a hillside.
Touring the site of the disaster on Saturday, President Enrique Pena Nieto said there was little hope of finding anyone alive.
Lt Carlos Alberto Mendoza, who is leading the team of soldiers searching La Pintada, said it was the most daunting task he had faced in more than two decades of service.
“They are doing unbelievable work, hours and hours for just one body,” he said of his team of 16 soldiers.
“No matter how hard the day is, they never get tired of working,” he added.
Continuing rainfall is putting the rescue workers at risk of renewed landslides.
Five police officers died on Thursday when their Black Hawk helicopter crashed into a hillside on its way to La Pintada.
A total of 1.2 million people were affected when Tropical Storm Manuel made landfall on 15 September on Mexico’s south-western coastline.
More than 25,000 tourists had to be airlifted out of Acapulco after the beach resort was cut off.
Just 24 hours after Manuel had made landfall, Tropical Storm Ingrid hit the country’s Gulf coast, causing destruction in Verazcruz and Tamaulipas.
After temporarily weakening, Manuel regained strength and hit Mexico’s north-western coast with hurricane-strength winds and more rain on Thursday.
Forecasters say rains will continue to fall on the Gulf Coast of Mexico and the country’s interior until Tuesday.