It added the 2018 outlook for Chinese investment in the United States doesn't look much better as the sides are now locked in an escalating fight over trade.
Trump wrote "we will make great progress together".
The speech at the Boao Forum for Asia in the southern province of Hainan had been widely anticipated as one of Xi's first major addresses in a year in which the ruling Communist Party marks the 40th anniversary of its landmark economic reforms and opening up under former leader Deng Xiaoping.
"Paying attention only to one's own community without thinking of others can only lead into a wall", Xi said.
He said "Cold War mentality" and arrogance had become obsolete and would be repudiated.
A joint report by the Rhodium Group and the National Committee on US-China Relations showed that Chinese investment in the US fell from $46.5 billion in 2016 to $29.7 billion a year ago.
Vice Premier Liu He had already vowed at the World Economic Forum in January that China would roll out fresh market opening moves this year, and that it would lower auto import tariffs in an "orderly way".
Tesla's Chief Executive Elon Musk has railed against an unequal playing field in China and wants to retain full ownership over a manufacturing facility the company is in talks to build there. China is of course very different. "Avoiding a trade war will benefit all countries", Musk tweeted after Xi's speech.More news: Four hurricane names are being retired and here are their replacements
Xi pledged specific measures to address concerns on IP protection.
Global stock markets recovered their poise Thursday and the price of oil came off three-year highs as investors digested U.S. President Donald Trump's defiant comments on the Middle East conflict. The Eurasia Group agreed the speech was "not a game-changer" and said it "underdelivers after all the hype from Beijing".
The report by the New York-based consultancy and the non-profit business lobby comes at a time of heightened friction between China and the United States over trade, and warns that "policy bellicosity especially from Washington" was casting a darker shadow over the economic relationship. "If the United States takes any action to escalate the situation, China will not hesitate to fight back".
Countries around the world should shoulder their responsibilities for global development, and expand cooperation to promote the building of a community with a shared future for humanity, Chinese President Xi Jinping said Wednesday.
According to an initial estimate, declines of exports up to 50 billion dollars would drag China's GDP growth rate down by less than 0.1 percentage point, Wang said.
The US has threatened to impose tariffs on as much as $150bn (£105bn) of Chinese imports in response to what it says are unfair Chinese trade policies that protect domestic markets while forcing foreign companies to hand over their technology and intellectual property. Beijing denies this charge.
The meeting was held before Trump instructed officials to consider tariffs on an additional $100 billion in Chinese imports, bringing the value of the nation's products set for higher duties to about $150 billion. In that speech he framed China as the world's new champion of free trade in an implicit rebuke to Trump. Those concerns took a backseat as President Donald Trump asked advisers to explore the possibility of the USA returning to trade talks with 11 Pacific nations to rejoin the Trans-Pacific Partnership.
China's first-quarter exports to the USA rose 14.8 percent from a year earlier, despite a 5.6 percent drop in March. "I think the time is gradually coming for China and the United States to negotiate".