The event is being attended by several foreign heads of government including Russian Prime Minister Dmitry Medvedev and Pakistani premier Imran Khan.
China imported $1.84 trillion of goods in 2017, up 16 percent, or $255 billion, from a year earlier.
In his speech, Xi vowed to "firmly punish behavior that encroaches on the lawful rights and interests of foreign companies, particularly intellectual property right infringements", adding the government will introduce a "punitive compensation institution" to "sharply raise the legal costs" of violating IPR.
"This provides huge opportunity to increase our exports to China which is further supported by the tariff war between U.S. and China", said Ajay Sahai, director general, FIEO.
"Trade and economic cooperation remain the anchor and propeller of a steady and healthy China-US relationship which is in essence mutually beneficial".
Ahead of the fair, the French and German ambassadors to China urged Beijing to take "concrete and systematic measures that go beyond tariff adjustments" to improve the business environment for foreign firms.
But none addresses USA complaints about its technology policy that prompted Trump to impose penalty tariffs of up to 25 percent on $250 billion of Chinese imports.
The China International Import Expo is part of official efforts to defuse trade tension while resisting pressure to roll back industry plans that Washington, Europe, Japan and other governments say violate its market-opening obligations.
"The world today faces many major problems that require close co-operation between China and the United States", Wang said.
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But experts are concerned the expo will lack bold new policies, favouring symbolism over substance.
With India's exports of United States dollars 13.33 billion, the trade balance is highly in favor of China.
High-level attendees include the presidents of Cuba, the Czech Republic, the Dominican Republic, Kenya, Lithuania, Panama, El Salvador, and Switzerland as well as the prime ministers of Croatia, Egypt, Hungary, Georgia, Laos, Malta, Pakistan, Russia, and Vietnam.
Through the expo China is trying to convey an image that it is not only interested in importing away materials and crude oil from other countries but also consumer products that in particular appeal to the country's 400 million "middle-income" residents.
Swiss President Alain Berset did not make the trip to China, despite being announced as among attendees by China's foreign ministry last week.
Some Western diplomats and businesses have been quietly critical of the expo, arguing it is window dressing to what they see as Beijing's long-standing trade abuses.
"As globalization deepens, the practices of law of jungle and victor take all are a dead end", Xi told the gathering in Shanghai, which featured more than 3,600 companies from 172 countries, regions and organizations. From the United States, some 136 exhibitors will attend, including Google, Dell Inc, Ford and General Electric.
For Iraq, it's crude oil. Tiny São Tomé is selling package holidays.