Washington  - US President George W Bush visited the Chinese embassy on Tuesday to sign a condolence book for the families of thousands who perished in the devastating earthquake a week ago.

Bush said the United States stands "ready to help" and praised the courage of Chinese rescue workers who continue to search for survivors.

"We extend our deepest sympathies," Bush said.

China's Sichuan province was hit by a 7.9 magnitude earthquake May 12 and a series of aftershocks since then, leaving at least 40,000 people dead and as many as
30,000 missing. The Chinese government has said the death toll could top 50,000.

The United States released an immediate 500,000 dollars in aid and was assessing additional ways to contribute to the ensuing humanitarian crisis. (dpa)