Hundreds of people remain unaccounted for in the remote mountainous region and the authorities fear the toll could rise sharply.
The fresh troops will join the more than 10,000 soldiers already racing to reach survivors cut off by washed out bridges and roads, the defence ministry said on Thursday.
'Mud lakes' danger
Al Jazeera's Steve Chao, reporting from the heart of rescue operations in the south on Thursday, said rescue teams were focusing on evacuating villages facing the new threat posed by the swelling "mud lakes".
He said the build-up of water and mud from days of heavy rain threatened to overflow onto villages that had been previously thought safe.
Heavy rains, which had made rescue efforts slow-going, eased off on Thursday, allowing helicopters to go deeper into the affected region to get a better assessment of the threat, our correspondent said.
Rescue teams were also taking advantage of the improved weather to airlift scores of survivors from villages already demolished by mudslides to safety in Cishan in Kaohsiung county, where a makeshift landing zone has been set up at a school.
Nearly 1,000 survivors who had made it to higher ground before walls of mud and rock covered their homes in at least three villages, were located on Wednesday, but heavy rains had made airlifting them out slow-going and dangerous, with helicopters only making a few dozen trips on Wednesday.
|Helicopters have been taking in supplies and ferrying out survivors [AFP]
Highlighting the continuing danger, funerals were held on Thursday for three rescue workers killed earlier this week when their helicopter crashed into a mountain in heavy fog.
In Cishan, relatives waited near the landing zone to learn the fate of their loved ones as each helicopter touched down with elderly men and women, small boys and girls and even infants, many looking dazed.
The tension among relatives was palpable and some have complained that the government should have accepted foreign offers to help with rescue efforts earlier.
The government says the US, Japan, China and Singapore have offered assistance but maintains it can cope on its own for now.
In Hsiao Lin, one of the worst hit mountain villages, hopes of finding survivors have faded after rescue teams found nearly the entire village wiped out by a mudslide.
The entire place had been enveloped by mud and only two out of about 200 homes remained standing, the rest either completely covered or washed away, our correspondent said from the scene.
|Almost the entire village of Hsiao Lin
was wiped out by the landslide
Only about 50 villagers managed to escape by climbing up to higher ground and more than 600 people were believed dead, witnesses said.
The mudslide occurred on Sunday morning when many people were still asleep and the village was more populated than usual because many children had returned to celebrate Father's Day in Taiwan on Saturday.
Rescuers arrived on Wednesday after battling through washed-out roads, unstable terrain and bad weather for days, but found little in the village left to rescue.
Villagers in the south appeared to have been taken by surprise by Morakot's arrival as the typhoon had been forecast to head north, but instead turned south to unprepared areas, our correspondent said.
Morakot, which had earlier killed at least 21 people in the Philippines, triggered the worst flooding in Taiwan in 50 years over the weekend before moving on to China.
It later weakened to a tropical storm but still wreaked havoc on China's southeastern coast, triggering massive landslides and forcing the evacuation of about 1.5 million people from the provinces of Zhejiang and Fujian.
It also damaged or destroyed more than 10,000 homes and flooded over one million acres of cropland, China's civil affairs ministry said.