US disaster assistance teams have reached tsunami-devastated American Samoa and were providing critically needed aid including emergency power and medical supplies, a top aid official said Thursday.

"A survivor walks through the ruins of Salebata village on the south coast of Samoa, in September 2009. US disaster assistance teams have reached tsunami-devastated American Samoa and were providing critically needed aid including emergency power and medical supplies, a top aid official said Thursday."

Federal Emergency Management Agency (FEMA) chief Craig Fugate said two disaster recovery teams arrived Wednesday and that initial assistance carried on through the night into Thursday on the small South Pacific island.

"We have over 140 people on the ground... coordinating and supporting the government's emergency response," including members of the US Coast Guard, the Hawaii National Guard and FEMA, Fugate told reporters on a conference call.

He said the US agencies had begun distributing food and water, power generators, medical supplies and other emergency aid.

Fugate would not give casualty figures for the US territory which President Barack Obama declared a major disaster zone, but Samoan officials said regional deaths had reached 148, including 31 on American Samoa.

The toll was expected to rise dramatically after the islands' worst quake in nearly a century unleashed walls of water that pounded the Samoan coastlines, echoing Asia's deadly 2004 tsunami that killed more than 220,000 people.

Despite scenes of devastation across the US territory and its capital Pago Pago, Fugate stressed that the LBJ hospital there "is operational" and that some 130 people with tsunami- and earthquake-related injuries had been treated there. The 75 patients who had been evacuated after the earthquake returned to the facility, he added.

"A rescue worker empties his boots during a break in the search at Litia Sini's Beach Resort near the village of Lalomanu on the southeastern coast of Samoa's Upolu island, seen here in September 2009. US disaster assistance teams have reached tsunami-devastated American Samoa and were providing critically needed aid including emergency power and medical supplies, a top aid official said Thursday."

FEMA, along with former president George W. Bush, was lambasted for its tardy response to Hurricane Katrina which inundated New Orleans in August 2005.

Fugate defended FEMA's response in American Samoa, saying "our teams went from no-notice to fully activated and deploying staff" on the island less than 40 hours after the disaster.

The FEMA chief said his agency was also closely monitoring the disaster in Indonesia, where officials said Thursday they fear thousands have died after massive earthquakes struck Sumatra, but that any initial US response will be made through the US Agency for International Development.

"We're very aware of the devastation there, and that the casualties will go up," Fugate said.

"We are going to continue to focus our response right now into American Samoa, but we are again ready to assist (in Indonesia) if we are requested to by USAID."