Taiwan has appealed for international technical assistance to help rescue more than 2,000 people stranded after Typhoon Morakot caused major mudslides.
The Taiwanese authorities say they need giant cargo aircraft able to drop large earth diggers and other machinery into remote mountain areas to re-open roads.
Correspondents say only Russia and the US are believed to have such aircraft.
Relatives of those stranded and of the hundreds feared dead have urged the government to speed up rescue efforts.
Many have been waiting for days at the rescue operation centre in Qishan for news of family members missing since the typhoon struck over the weekend.
Hundreds of people feared buried by mudslides in the south of the country have been found alive.
But Taiwan’s President Ma Ying-jeou – who visited the area on Wednesday – said hundreds more were likely to have died. The number of confirmed dead stands at 108.
The Taiwanese government is sending more than 4,000 extra soldiers to speed up rescue efforts, with thousands already working to reach areas cut off when roads and bridges were swept away.
Speaking while inspecting the rescue operations, President Ma said: "We welcome all forms of aid, and we also need equipment, especially helicopters that can carry cranes."
He assured anxious relatives waiting for news that no effort would be spared to find their loved ones.
So far rescues have been carried out only by helicopters, but that has been a slow process.
While typhoons are common in Taiwan at this time of the year, this one caught people by surprise, dumping about half the average annual amount of rainfall in many places, and about two-thirds in the worst affected places.
The authorities also need 1,000 pre-fabricated houses for families left homeless, correspondents say, as well as supplies of disinfectant to help prevent disease spreading.
Nearly 14,000 people have now been evacuated by air from the worst-affected areas. Military helicopters have been dropping provisions for others, but continuing rain has hampered their efforts.
It is now confirmed that all three crew aboard a rescue helicopter which crashed in bad weather on Tuesday were killed.
The typhoon struck Taiwan at the weekend, causing the worst flooding in 50 years.
The BBC’s Alastair Leithead, at the Qishan rescue base, says thousands of extra Taiwanese troops have been drafted in to help the rescue efforts.
The military is now trying to push out into remote areas on foot as well as by helicopter to establish who is most in need of help, he says.
According to news reports, a wooden sign saying "32 dead, SOS" was posted by a collapsed bridge at the only entrance to one village, Hsinfa, on Wednesday. Several survivors were pulled to safety using ropes thrown across the river.
Deluged Taiwan with at least two metres (80in) of rain over the weekend
Caused the country’s worst flooding in 50 years
Some 108 people confirmed dead, hundreds unaccounted for
Some 14,000 people airlifted out of affected areas
The National Fire Agency said about 200 people were awaiting rescue from a hot spring resort in Liukuei, while the military said it had found another 700 survivors in the area and was starting to move them to safety, the AFP news agency reports.
Villagers in some areas are at further risk as lakes created by floodwaters burst their banks, relief official Hsu Chin-biao told the Associated Press news agency.
Some 300 people in the township of Taoyuan had been told to run to higher ground about half an hour before floods crashed down when an embankment holding back a lake gave way, he said.
Typhoon Morakot, which lashed Taiwan with at least two metres (80in) of rain over the weekend, has caused at least $225m (£135m) in agricultural damage and left tens of thousands of homes without power and water.
TAIWAN’S WORST-AFFECTED AREAS
Qishan – rescue operation centre established here, thousands of troops drafted in to help.
Liukuei – 200 people awaiting rescue from hot spring resort, with another 700 survivors in the area.
Hsinfa – 32 people reported dead, survivors pulled to safety using ropes thrown across river.
Hsiaolin – hundreds feared dead following mudslides the morning after Taiwan’s Father’s Day.
Taoyuan – residents told to run to higher ground as embankment holding back lake gave way.