Shanghai kicked off the six-month World Expo on Friday with a star-studded gala ceremony set to end in a lavish blaze of fireworks and light along the city's river-front.
Still basking in the glow of its successful staging of the 2008 Beijing Olympics, China is treating the Expo as an equally important showcase for its growing political and economic clout.
From the United States to North Korea, a total of 189 countries will take part in the six-month display of ideas, culture and technology expected to attract at least 70 million visitors -- the vast majority of them Chinese.
"Expo 2010 Shanghai is now open!" Chinese President Hu Jintao declared, after the national anthem rang out in the Expo cultural centre and the flags of all participating countries were paraded through the giant hall.
Hong Kong action film star Jackie Chan serenaded thousands of guests including 20 world leaders to open the event.
The gala -- set to end with a fireworks and light show planned by the team behind the opening and closing ceremonies for the Vancouver Winter Olympics -- was a departure from past World Expos, with an all-star line-up.
Italian pop tenor superstar Andrea Bocelli, Chinese pianist Lang Lang and the Soweto Gospel Choir from South Africa were expected to join Chan as part of the extravagant festivities.
"We look forward to stunning the world," said Ignatius Jones, the artistic director of the ceremony, which is to feature huge fireworks and a chain of searchlights along a 3.5-kilometre (two-mile) stretch of Shanghai's riverfront.
Once Expo's gates open to visitors on Saturday, participating countries will vie to outdo each other in presenting the best they have to offer the world -- with a particular eye on China's market of 1.3 billion people.
Denmark has made a splash by bringing its "Little Mermaid" statue out of Copenhagen for the first time, France has impressionist paintings and Rodin sculptures, while Italy is showing works by Renaissance master Caravaggio.
India is bringing a cast of Bollywood stars and Canada's pavilion will bear the imaginative touches of contemporary circus troupe Cirque du Soleil.
Past Expos are remembered for leaving architectural landmarks such as the Eiffel Tower in Paris and the Space Needle in Seattle, and introducing the television and electric lighting to a mass audience.
In Shanghai, the spotlight will be on the cutting-edge design of the national pavilions at the 5.3-square-kilometre site.
Highlights include China's red inverted pyramid, Britain's stunning dandelion-like "Seed Cathedral", Spain's "Big Basket" made of 8,500 wicker panels, and Switzerland's three-story-high "meadow" -- complete with chairlift.
China has bolstered security for Expo, deploying paramilitary police, randomly checking foreigners' identification and searching car and rail passengers entering and leaving the city. Ships will also be searched.
Shanghai has spent 400 billion yuan (about 60 billion dollars) in direct and indirect investments preparing for the Expo, according to state media -- more than was spent on the Beijing Olympics.
Human rights groups have protested against the silencing of dissidents ahead of the event, and the apparent denial of accreditation to journalists from a Hong Kong-based newspaper known for its strong pro-democracy stance.
"The Shanghai Expo hasn't even started yet, but already the Chinese government appears willing to use a high-profile international event to demonstrate its lack of tolerance for universal rights and freedoms," said Sophie Richardson, Asia advocacy director at Human Rights Watch.