Trying to restart a slowing economic growth, China's President Xi Jinping has decided to deepen the reform and open up the country wider to the outside world.

"China will stay strongly committed to deepening its reform on all fronts while opening still wider to the outside world," Xi told the Wall Street Journal in a written interview before he departed for an official state visit to the United States on Tuesday.

This was the second time in a week that the president reassured the market, that the policies which brought wealth and prosperity to China's people will continue, deeper and wider.

Last week, Xi told a room of former U.S. officials and business leaders that China is fully committed to reform and opening up and he hoped they would actively support it.

While China and the United States are expecting much from Xi's visit, China-Britain cooperation has born fruit. On Monday, the two countries reached 53 agreements on nuclear energy, high-speed railway, infrastructure among many others at the 7th China-Britain Economic and Financial Dialogue in Beijing.

Notably, China suggested opening up its closely controlled financial market, allowing British institutional investors to trade securities in China, and mulling a mechanism to connect the Shanghai and London exchanges.

Premier Li Keqiang told visiting British Chancellor of the Exchequer George Osborne that China is ready to cooperate in an open and inclusive manner.

These agreements indicated that opening up has reached levels unthinkable decades ago.

Since the incumbent central leadership was formed in late 2012, China has introduced many new measures to foreign investment and trade.

China is actively seeking a bigger say in international affairs, by participating in and increasingly initiating, global cooperation.

The Asian Infrastructure Investment Bank and the Belt and Road initiative are among China's efforts to supplement the existing international order and overhaul global governance.

The phrase "opening up" frequently appears in policy statements and headlines at a time when China needs to find new sources of growth.

During a tumultuous summer, Chinese stocks were hit by repeated plunges and most of economic indicators were soft. Worries arose about whether China can sustain medium-to-high speed growth. Reform and opening up is China's solution. Last week, Xi said opening up and reform will add new impetus and vitality to the economy and provide new room for growth.

"China should be committed to attracting foreign investment and expertise, and improve opening-up policies," he said, addressing the 16th Meeting of the Central Leading Group for Deepening Overall Reform.

"The government will not change its policy toward foreign investment, and will protect the lawful interests of foreign-funded companies and provide better services for them," said a statement released after the meeting.

China promised to make a national "negative list" by 2018, of sectors which are not fully open to all market entities, both domestic and overseas. Border areas will explore new models of cross-border cooperation and new mechanisms for regional growth.

More state-controlled sectors will be opened to private investors and it will be easier for foreigners to apply for permanent residence permits.

China is becoming more interdependent on and interrelated to the world economy, said John Thornton, co-chair of Washington-based think tank Brookings Institution.

Regional and global cooperation and policy coordination can yield results satisfactory to all, he said.

"China has been on a course of reform and opening up for almost 40 years. That trend will continue," said Thornton.