Addressing troops and villagers, he urged them to build buildings stronger than those that had collapsed under the weight of rocks and mud.
"Flood disasters can happen, can still happen at any time," he said.
"We must be well prepared. By uniting together, and through our collective effort, there is no doubt that we can overcome this disaster."
Thousands flee homes
At least 107 other people were missing and more than 10 million people had been affected by the floods, the government announced.
Torrential downpours have triggered flash floods, inundated crops, and disrupted traffic and telecommunications, forcing the evacuation of 862,000 people, the state-run Xinhua news agency reported on Sunday.
The worst hit areas were the provinces of Fujian, Jiangxi, Zhejiang, Hunan, Guangdong, Sichuan, and Guizhou, the Guangxi autonomous region and Chongqing municipality.
In Yujiang county in Jiangxi, flash floods cut a 30m section out of a main road on Sunday morning, state telelvision reported.
Bridges swept away
Al Jazeera's Harry Fawcett, reporting from the southwest Fujian province, said local residents of one village had to create their own methods of survival after floods swept away a bridge connecting the village to the main road.
"For four days, [villagers] say they've had no food and no access to the outside world," he said.
"Emergency workers did come down here [and] constructed a rope pulley system, which took some bags of rice across. But [villagers] are having to respond by themselves creating their own improvised bridge.
"So even though the rain is easing off in this region, the impact and the effects of these floods will continue for some time across several regions and provinces across southern China."
The government has estimated damage caused so far to be around $1.5bn.
The storms have collapsed reservoirs, overflowed rivers, caused landslides and power outages, and damaged highways, China's disaster relief agency said.
Nine local officials in the Guangxi Zhuang Autonomous Region have been punished for dereliction of duty in flood work, including a reservoir monitor caught playing poker, the state-run China Daily said.