Preparations for the World Expo 2010 Shanghai China were going according to plan, and construction of most pavilions is nearly complete, said an organizing official Monday.

Yang Xiong, deputy director of the Executive Committee for Shanghai Expo and Vice Mayor of Shanghai, said in Beijing at a press conference organized by the State Council Information Office, just 103 days ahead of the 2010 Shanghai Expo opening, that preparations were in the final stages.

A total of 192 nations and 50 international organizations had confirmed their participation to date. All 31 provinces, autonomous regions and municipalities on the mainland, along with Hong Kong, Macao and Taiwan would participate.

"More than 220 countries and international organizations have confirmed the will join the 'on-line' World Expo, giving users a great Expo experience on the Internet," said Yang.

Ninety percent of the pavilions' construction was complete. Of the 42 pavilions built by foreign countries, 80 percent had started decorating.

The coordinators were making efforts to ensure security and food safety, as well as traffic flows, said Yang. Tourists would be warmly looked after.

The Shanghai Expo will run from May 1 to Oct. 31, 2010, and as of Jan. 17, more than 18 million tickets had been sold, according to the official Expo website.

Yang estimated the Expo would receive around 70 million visitors, or more than 400,000 per day on average, a challenge to the city's transportation system.

He said most new traffic construction projects for the Expo, including central ring road and new subway lines, were completed and open to traffic, and ferry and streetcar lines across the Huangpu River would be completed within three months.

"More than 90 bus routes and five subway lines cross the Expo area, and 42 buses will run within 2.4 kilometers of the area." he said.

"The public transportation system can meet the demand of all the visitors. But traffic jams could still happen during rush hours," he said.

The municipal government was planning to add new trains to subway lines to alleviate pressure on traffic, he said.

"Carbon levels are also a concern. All the buses in the Expo use green energy like electricity," said Hong Hao, director of the Bureau of Shanghai World Expo Coordination.

Hong said that the Expo would use solar power units that could generate up to 4.6 megawatts, and the lighting system would use light-emitting diodes to save electricity.

"We have machines in major facilities to collect rain water for irrigating the green areas, which cover one third of the Expo area. We have even rebuilt old factories into pavilions." he said.

Hong estimated that these measures could reduce total carbon emissions of the Expo by 60 percent to 70 percent.