President Xi Jinping tours the Boeing factory in Everett, Washington, on Wednesday.?

President Xi Jinping, addressing CEOs from 30 leading companies on Wednesday, said that China was taking steps to make its markets more accessible.

"China is pursuing a new round of opening-up," Xi said at the US-China Business Roundtable in Seattle on the second day of his US visit. It is "significantly removing restrictions on market access for foreign investments".

His economic policy speech was geared toward reassuring the companies that growth in China would remain positive in the long run and that China would open further to the outside world. He also called for the conclusion of a high-standard Bilateral Investment Treaty between the two countries.

"Without reform, there will be no driving force; without opening up, there will be no progress," Xi said through an interpreter to the group, which included billionaire investor Warren Buffett, Amazon.com founder Jeff Bezos, Apple Inc CEO Tim Cook, Jack Ma of Alibaba Group Holding, Pony Ma of Tencent Holding Ltd, and Yang Yuanqing of Lenovo Group.

Xi acknowledged the "moderation in speed and downward pressure with some ups and downs in the stock market" when speaking of China's economy, but he said the long-term positive trend will remain and the country will continue to provide vast markets and support to the global economy.

"China-US business cooperation has enormous potential," Xi said.

Last year, China attracted $128.5 billion in foreign direct investment, becoming the world's top destination for FDI for the first time.

Xi encouraged US companies to set up regional headquarters and research and development centers in China, and he welcomed small and medium-sized enterprises to invest in China.

The president toured a Boeing Inc assembly line in Everett, Washington, earlier on Wednesday as the company announced it had won orders and commitments from China for 250 narrow-body 737 aircraft and 50 wide-body aircraft, valued at about $38 billion.

Boeing and Commercial Aircraft Corp of China Ltd also announced that they will open a facility in China to paint, complete the interiors of, and deliver 737 aircraft to Chinese companies.

On the Bilateral Investment Treaty, currently being negotiated between China and the US, Xi said that "once concluded, the treaty will further ease market access and put in place more open and transparent market rules".

Xi said he hoped that both sides will push to finalize the treaty ahead of schedule.

Henry Paulson, former US Treasury secretary, said: "Both of our countries are essential to global growth. Yet both countries must carry out structural reforms to move their economies into a more growth-conducive footing for the long term and find ways to address issues such as commercial cyber-theft and climate change.

"Despite many challenges, there are vastly more areas for cooperation than ever before," Paulson added.

A closed-door discussion moderated by Paulson preceded Xi's address.

According to a news release from the Paulson Institute, the US and Chinese CEOs discussed increasing investment in each other's markets, and both sides expressed a desire for increased access for business.

The US CEOs also noted the importance of addressing intellectual property protection and called for common standards and transparent regulations. Both the US and Chinese CEOs highlighted opportunities for cooperation on clean technology projects.

Other CEOs in attendance were Mary Barra of General Motors Co, Dave Cote of Honeywell Co, Robert Iger of The Walt Disney Co, Ellen Kullman of E. I. du Pont de Nemours and Co, Andrew Liveris of Dow Chemical Co, Satya Nadella of Microsoft Co, Indra Nooyi of PepsiCo Inc, Dennis Muilenburg of Boeing, Ginni Rometty of IBM Corp and Howard Schultz of Starbucks Corp. Tom Pritzker, executive chairman of Hyatt Hotels Corp, and John Chambers, executive chairman of Cisco Systems Inc, also attended.