Chinese President Hu Jintao declared the opening of the World Expo 2010 in the Expo Culture Center in Shanghai Friday evening.

Hu's announcement was echoed by thunderous cheers from spectators in the seashell-shaped venue at the Expo park, which spreads across 5.28 square kilometers along both sides of the Huangpu River.

Among the spectators, French President Nicolas Sarkozy and Republic of Korea President Lee Myung-bak were in attendance along with other world leaders, including Mongolian President Tsakhia Elbegdorj and European Commission President Jose Manuel Barroso.

The Shanghai World Expo, carrying the theme of "Better City, Better Life", will lead new lifestyles, promote harmony between man and nature as well as the overall development of human beings, Chinese Vice Premier Wang Qishan said while addressing the opening ceremony.

International Exhibitions Bureau President Jean-Pierre Lafon said he hoped the Shanghai World Expo would contribute to a social awakening so that cities may become more sustainable, fairer, safer and more harmonious.

It was the first time for the 159-year-old World Expo to be held in a developing country since the inaugural fair in London in 1851.