Indonesia's president said Monday his country was still living a nightmare more than three weeks after the tsunami (search) hit, while the leaders of Sweden, Norway and Finland toured beaches in Thailand where many of their countrymen died.

Sri Lanka (search) officials estimated their death toll could rise above 40,000, which would bring the overall toll from 163,000 to above 170,000, while Japanese aid workers in Indonesia paused to silently rememberg to comprehend the devastation he saw by helicopter over Sumatra island, which was closest to the Dec. 26 magnitude-9.0 earthquake that spawned killer waves in 11 nations.

"Not only do you see where the houses once were, but you can see the destroyed remnants of the houses. It is devastation that's hard to comprehend," Australian Defense Minister Robert Hill told reporters in the capital of Sumatra's Aceh province.

Indonesian President Susilo Bambang Yudhoyono (search) said his country was "still living the nightmare of the aftermath of the horrific earthquake and tsunami," while aid workers in Aceh said the tsunami took a heavy toll on those most needed now: health professionals.

"There has been a whole generation of nurses and doctors just killed," said Lt. Col. John Crozier, an Australian surgeon helping out at a hospital in Aceh's provincial capital.

The death toll in one of the world's worst natural disasters stood Monday at nearly 163,000, with more than two-thirds of the deaths in Indonesia.

Sri Lanka's Public Security Ministry on Monday raised its national tally by 7,000 deaths to more than 38,000, while the country's National Disaster Management Center maintained its official figure of only 31,000 deaths. It was not immediately clear why the two agencies had conflicting figures, but both said they expected the confirmed deaths eventually to rise above 40,000.

In Indonesia, hundreds of troops from Australia, Singapore, Germany and other nations are helping the relief effort, led by nearly 15,000 U.S. troops — most of whom are docked off the coast of western Sumatra island.

On Sunday, Jakarta backed away from an earlier call for troops to be out of Indonesia by March 26 — three months after the earthquake-tsunami disaster.

Japan is preparing its biggest-ever overseas military relief effort, a mission involving 1,000 troops expected to arrive soon in their first deployment to Indonesia since World War II.

Japanese aid workers already in the country halted work Monday to commemorate the 6,500 people killed when an earthquake ripped open the Japanese port city of Kobe 10 years ago.

"I think everybody here prayed for those victims," said Tatsuro Kai, a 53-year-old doctor working in Banda Aceh.

A U.N. conference in Kobe on Tuesday will focus on creating a tsunami warning system for southern Asia that could have averted many of the deaths.

The tsunami wasn't the deadliest catastrophe in memory — a 1970 cyclone in Bangladesh killed 300,000, and a 1976 quake in Tangshan, China, killed more than 240,000 — but it spanned 11 nations and struck a tropical band popular with tourists, making it a truly global disaster.

"You must all realize that this catastrophe is a catastrophe that we share," Prime Minister Goeran Persson of Sweden said ahead of his tour Monday of Thai beaches along with prime ministers of Norway and Finland. He said no one knew exactly how many Swedes were victims, but "We fear there may have been several hundred, in the worst case more than a thousand."

More than 2,000 Swedes, Finns and Norwegians remain missing.

Of the 1,900 missing Swedes, about 20 percent are estimated to be 20 years old or younger. Sweden says 52 of its citizens were confirmed dead. Finland reported 15 dead and 174 missing. Norway says 12 of its citizens were killed and 77 missing.

Rebuilding the devastated public health system in Indonesia's Aceh province must be a top priority and will take years, said Mark Collins, a team leader for Australia's international development agency AusAID.

Crozier, the Australian surgeon, said the disaster killed 350 of the 900 staff members at the 450-bed Dr. Zainoel Abidin Hospital in Banda Aceh.

"Most public health infrastructure has been seriously damaged or destroyed," Collins told a news conference there. "There was also the tragic loss of many trained personnel in the health sector."

Of the 400 staff who worked in the province's health department, only 82 — or about one-fifth — have been accounted for, Collins said.

There have been no major illness outbreaks, despite early fears that tainted water supplies would spur cholera. But the World Health Organization said it remains concerned over malaria spread by mosquitoes breeding in the waterlogged coasts of tsunami-hit countries.

"There is still significant risk to health. People are still drinking dirty water. There is a malaria threat," said Rob Holden, a WHO coordinator.