"We've come to express our country's condolences for those who mourn for the loved ones," Bush said after his visit. "We stand ready to help in any way that the Chinese government would like. We know there's great courage being displayed ... as rescue workers search for those who may still be living."
Chinese officials said at least 40,000 people were confirmed dead from last week's earthquake in Sichuan province.
The message the Bushes left in the book extended condolences of the American people and noted the "generosity of spirit and the strength of character shown by the Chinese people as you confront this natural disaster."