The United States pledged its full support for Asian recovery efforts from the December 26 tsunami that has claimed nearly 150,000 lives in 12 countries rimming the Indian Ocean.

Colin Powell, right, with Indonesian Foreign Minister Hassan Wirayuda, center, and Florida governor Jeb Bush

U.S. Secretary of State Colin Powell pledged on-going U.S. assistance to Asian nations devastated by the December 26 earthquake and tsunami. Mr. Powell met with Thai Prime Minister Thaksin Shinawatra Tuesday in Bangkok and discussed long-term reconstruction.

"We of course have made it clear we will do everything that is necessary to support the countries in the region," he said.

Mr. Powell toured the resort island of Phuket, Thailand's worst hit area. Thailand is one of 12 affected nations and the first stop on the secretary's trip.

The U.S. government has now pledged more than $350 million in assistance to the region. The United States is also conducting a major military relief effort using Thailand's Utapao Air Base as a staging area for aid flights and supplies.

The U.S. secretary of state and Mr. Thaksin agreed to work towards the creation of a tsunami early warning system - to prevent future catastrophe. This will be a key topic when leaders meet in Jakarta Thursday for a one-day disaster conference.

Mr. Powell, in a Thai television interview, said the scale of this tragedy was overwhelming.

"I've never seen one single event that affected 12 countries and caused such incredible loss of life," he stated. "And when you see what's happening in Indonesia and in Sri Lanka it truly is a tragedy of enormous proportions."

Rubble in Banda Aceh, Indonesia from tsunami damage

Indonesia was the hardest hit from the earthquake and tsunami with close to 100,000 dead, tens of thousands missing and more than 300,000 refugees.

The massive aid and recovery effort continued Tuesday as emergency food, water and other support continued to reach desperate populations.

United Nations children's fund chief executive, Carol Bellamy, says in Sri Lanka the main challenge now is to prevent an outbreak of disease. "Making sure that kids will [drink] clean water, that there is some sanitation, that the medicines they need are there to avoid outbreak of malaria, dengue, or diarrhea - which could lead to death," said Ms. Bellamy.

World Food Program officials believe progress is being achieved in the hardest hit areas such as Indonesia's Aceh Province. In Sri Lanka, the WFP will have dispatched more than five thousand tons of food to 750,000 people by week's end.