(CNN) -- Vietnamese Prime Minister Nguyen Tan Dung urged authorities Wednesday to "urgently implement" relief efforts after Typhoon Ketsana slammed into the country hours earlier.
A man walks by a lake alongside the national north-south highway near Danang, Vietnam, on Tuesday.
The prime minister said in a written statement that he sent his "profound condolences to the families of killed and wounded," and to those who suffered damage to their homes and property.
The government did not say how many people had been killed or were reported missing. Numerous news agencies reported the deaths of more than a dozen people. CNN could not independently verify the reports.
The prime minister said resources in several provinces would be focused on searching for missing people; treating the wounded; moving those in flooded areas; and providing people with food and water.
After it struck central Vietnam, Ketsana weakened to a tropical storm, forecasters said.
"The system is expected to completely dissipate over land within the next 12 hours as it continues to track to the west," the Joint Typhoon Warning Center said in its final statement issued on the storm at 11 a.m. Tuesday ET. Watch a report on the storm from Vietnam »
Aid agencies reported that amid flood warnings, about 200,000 people were evacuated from low-lying areas to community centers and schools on higher ground.
"Today was pretty bad, they say that this is the worst of it," iReporter Jeff Puchalski, 43, told CNN, speaking from Danang. "It was very strong winds," he said. Watch video from Puchalski »
Puchalski, who lives in Ho Chi Minh City, was staying at a resort in Danang. His video from outside the resort showed tiles falling from the roof and littering the ground. Although he had intended to stay only for a weekend, he said he was stuck there until the storm passed.
"We're also getting very heavy rains," he said.
Ketsana's maximum winds were reported at 167 km/h (104 mph) with gusts as strong as 204 km/h (127 mph) as it crossed over the South China Sea and approached land.
The city of Hue, Vietnam, picked up an estimated 13 inches of rainfall in a day, according to CNN Meteorologist Jennifer Delgado. Are you there? Share your story or pictures
The global relief agency World Vision said the Vietnamese government had shut down airports, schools and power in the Danang area, three hours from Hue.
Danang is predicted to be in the eye of the storm. "It's very windy, and trees have already blown down," said Le Van Duong, World Vision's emergency response coordinator in Danang.
"We have seen the evacuation of 3,000 families from our project areas to safer places, including schools, and we have already distributed noodle packs to 700 families."
Ketsana left at least 246 people dead as it passed over the Philippines. Another 38 people were missing, according to the nation's National Disaster Coordinating Council. Nearly 2 million people were affected by the killer storm, and 567,000 people had been evacuated.
The international community rallied Tuesday to help desperate Filipinos avoid a humanitarian catastrophe. See incredible images of flooding in the Philippines »
Several nations, including the United States, Australia, Japan and China, have donated money for relief supplies. U.N. Secretary-General Ban Ki-moon said the United Nations was considering an emergency appeal for aid as several U.N. agencies pledged support. The World Food Program said it would provide rations to 180,000 people.
Floodwaters were subsiding in the capital, Manila, which was hit with the heaviest rainfall in 40 years and, at one point last weekend, was 80 percent under water. Watch how people of Manila are coping »
Manila, on the island of Luzon, and the nearby province of Rizal bore the brunt of the storm. People huddled on rooftops waiting on army helicopters to pluck them to safety. Others used ropes to wade through waist-deep muddy waters.
Power and water supplies failed in some areas. Roads were rendered impassable, making rescue efforts challenging.
Ketsana is expected to move west across Vietnam into neighboring Laos and Thailand.
Journalist Asha Phillips contributed to this report.