The principle of one country, two systems has been a universally acknowledged success in the past 20 years, according to Zhang Xiaoming, director of the central government's Liaison Office in the Hong Kong Special Administrative Region.

Zhang said that no matter what difficulties and challenges arise, confidence and determination in the principle will not be shaken. "The principle is designed to ensure China's sovereign rule over Hong Kong and Macao without changing their capitalist systems and existing ways of life, and it should not be misinterpreted by certain ill-motivated forces as pulling the SAR away from the country," Zhang said in a recent interview.

He said facts in the past two decades since Hong Kong was returned to China have proved that the principle is not only the best solution to solve the Hong Kong question, but also the best system to maintain its long-term prosperity and stability.

According to the SAR government, Hong Kong's GDP saw an annual increase of 3.2 percent from 1997 to 2016, and the region's unemployment rate has remained low at 3.5 percent or less during that period.

He said the region's capitalist system and its core values, including justice, freedom and the respect of law, as well as the intolerance to corruption, have not changed.

Last year, more than 13,000 assemblies and parades were permitted, which is more than 30 a day, according to the SAR government. A report by the World Bank also indicated that Hong Kong's rank regarding the quality of rule by law jumped from 60th in 1996 to 11th in 2015 among more than 200 countries and regions worldwide.

With the implementation of the Closer Economic Partnership Arrangement, Shanghai-Hong Kong Stock Connect and Shenzhen-Hong Kong Stock Connect, and the regional joint development plan of Guangdong-Hong Kong-Macao Great Bayarea, Zhangsaid Hong Kong is enjoying its historical chances for future development.

The trade volume between the two sides reached HK$3.8 trillion ($487 billion) last year, 2.5 times that of 1997, while about 43 million mainland tourists visited Hong Kong, nearly 18 times the number 20 years ago, according to Zhang.

Major infrastructure construction work to bridge Hong Kong and the mainland will be finished soon, which Zhang said will strengthen economic ties and bring more chances for cooperation with mutual benefit.

The Hong Kong-Zhuhai-Macao Bridge is scheduled to be put into use by the end of the year, according to Jimmy Chan Pai-ming, principal government engineer.

The bullet train that connects Shenzhen and Guangzhou in Guangdong province with Hong Kong also is estimated to be finished before September 2018, according to Vincent Lin, project development manager for Hong Kong's Mass Transit Railway Corp.

"Our previous experience has proved that the one country, two systems principle has a strong vitality and is never behind the times. We see a rainbow after the rain. Through the baptism of challenges, success of the principle is convincing," he said.

yanwanli@chinadaily.com.cn