Updated

President George W. Bush (search) expressed his condolences to the victims of the massive earthquake and tsunamis that hit southern and southeast Asia. The State Department said three Americans have been identified as being among those killed.

State Department spokesman Noel Clay said Sunday two Americans were killed in Sri Lanka (search) and one in Thailand. He said a number of other Americans were injured, but he had no details. The three Americans were not further identified.

"We're working out on ways to help. The United States will be very responsive," said Clay. He had no details on plans for relief and assistance.

Deputy presidential press secretary Trent Duffy said in a statement, "The United States stands ready to offer all appropriate assistance to those nations most affected."

The White House statement, issued aboard Air Force One (search) en route to Texas from Washington, said "the president expresses his sincere condolences" over the "terrible loss of life and suffering" caused by the earthquake and tsunamis that hit six countries.

An estimated 10,000 people are believed to have been killed by the massive waves with the most severe death toll in India, Sri Lanka, Indonesia and Thailand.

The statement said U.S. relief efforts were already underway to help people in Sri Lanka and the Maldives, a string of 1,192 coral atolls off the southwestern coast of India.

"We will work with the affected governments, the United Nations, non-governmental organizations, and other concerned states and organizations to support the relief and response to this terrible tragedy," said the statement.

"Certainly, our thoughts and prayers are with those families and loved ones who have experienced a loss of life," said Duffy.

The 8.9-magnitude earthquake, centered off the west coast of the Indonesian island of Sumatra, caused tsunamis to roll across the Bay of Bengal.

"The United States stands ready to offer all appropriate assistance to those nations most affected including Sri Lanka, the Maldives, Thailand and Indonesia as well as the other countries impacted," said the statement.