The death toll in Taiwan in the wake of Typhoon Morakot is expected to reach about 500, President Ma Ying-jeou said Friday.
Ma called a national security conference on Friday and urged officials to step up rescue and relief operations.
"While the rescue operation is still going on, we have started rehabilitation and reconstruction work, which is just as imminent but might be even more difficult and cumbersome," Ma said.
The devastation left by Morakot is the worst the island has seen in 50 years, Ma said.
Morakot struck Taiwan on the weekend and dumped more than two metres of rain before moving on to China.
Morakot destroyed the homes of 7,000 people and caused agricultural and property damage in excess of 50 billion new Taiwan dollars ($1.5 billion US), Ma said.
Ma's government has come under criticism since the storm, with allegations of slow rescue efforts.
The government has said its work has been hampered because of the destruction of 34 bridges and 253 sections of road, as well as continued poor weather and lakes created by the storm that are bursting embankments and flooding into more villages.
Rescuers have relied on helicopters to reach the worst-hit areas, and on Thursday officials added 4,000 troops to the relief efforts. Requests to foreign governments have been made for helicopters capable of carrying earth-moving equipment and shelters.
But many villagers have complained they had to mount their own rescue operations and cleanup efforts.
If authorities had moved sooner and faster, more people could have been saved, villagers told officials who visited the worst-hit areas this week.
Taiwan's official death toll was raised to 120 on Friday with 59 also cited as missing.
But hundreds are unaccounted for and many people are expected to have died after becoming trapped in mudslides that were brought on by the storm.
Official figures do not yet include the people believed to have been buried, said Wang Chi-eng, a spokesman for the country's relief operations.
But estimates now indicate up to 400 people died in Shiao Lin, which was worst hit by the slides, Wang said.
The mudslides in the mountainous south wiped out entire villages. In Shiao Lin only two buildings remained standing after the muck and debris plowed over the village.
"The flood came so suddenly and with a tremendous roar. It destroyed everything in the village," said survivor Li Wen-chuan, 68. "This is the worst thing that has ever happened to me. My life will never be the same."
Given up hope
Though the military finally opened a road to Shiao Lin, authorities have given up hope of trying to find the people believed to be buried under the tonnes of mud in the village, said Kaohsiung County chief Yang Chiu-hsing.
A memorial will be built at the site of the village, which previously housed about 170 homes, Yang said.
A total of 15,400 villagers have been ferried to safety since the rescue efforts began, according to officials.
Rescue workers continued their work to try to retrieve the more than 1,900 villagers believed to still be stranded near remote villages after the storm.
Harrowing rescues continued on Friday, as soldiers worked to pluck frightened survivors from rocky mountain faces, sometimes having to deal with raging rivers. The rescuers used makeshift zip lines strung over washed-out bridges and roads.
Army crews have moved into some villages and are using heavy machinery to clear mud from roads. Some residents are also returning to their homes and businesses and attempting to dig out their livelihoods.