United Nations Secretary-General Kofi Annan says it will take up to 10 years to rebuild areas of southern Asia devastated by last week's tsunami and earthquake.
Mr. Annan says the disaster is the largest the U.N. has ever dealt with.
The tsunami wreaked havoc from Malaysia to east Africa, leaving at least 127,000 dead.
Mr. Annan will head to south Asia later this week for a summit on relief efforts. World leaders attending the conference in Jakarta, Indonesia, will also make an appeal for more aid.
The international community has pledged $2 billion so far.
U.S. Secretary of State Colin Powell heads to the region today to inspect damage in Thailand and Indonesia.
He told NBC television the $350 million pledged by the United States may have have to be increased, saying the catastrophe is one of the worst the world has ever seen.
Some information for this report provided by AP and Reuters.