Chinese President Xi Jinping attended a ceremony marking the 20th anniversary of Hong Kong's return to China at the Hong Kong Convention and Exhibition Center.

The Special Administrative Region's new Chief Executive Carrie Lam Cheng Yuet-ngor and her cabinet were sworn in at the ceremony, with Xi administering the oath of office.

Xi Jinping: "One Country, Two Systems" a success

Xi gave a speech at the ceremony, outlining Hong Kong's achievements over the past two decades.

He said the return of Hong Kong marked a major step towards the reunification of China and the implementation of "One Country, Two Systems" in the special administrative region had been a success.

"It provides a formula for the international community in addressing similar issues," Xi said.

Xi said Hong Kong should accurately and comprehensively implement the "One Country, Two Systems" principle.

"The 'One Country' is the root," Xi said, adding that creating differences and provoking confrontation would not resolve problems.

He urged Hong Kong people to always act in accordance with the Constitution and the Basic Law and enhance awareness of the law among the public, especially young people and civil servants.

Xi also stressed the significance of development, as he hopes Hong Kong can maintain its status as a global financial, trading and shipping center and obtain opportunities from cooperation with the mainland like the Belt and Road Initiative.

Carrie Lam: Let all Hong Kong residents have hope and happiness

In her speech, Lam highlighted her vision for the next five years. Noting "One Country, Two Systems" as the foundation for Hong Kong's development, Lam said she would uphold the rule of law and take a firm stance to fight against any activities violating sovereignty, stability and national interests.

She stressed her efforts to maintain Hong Kong's economic growth and encourage innovation, maintaining Hong Kong's standing as a place with high competitiveness.

"My vision is to let all residents in Hong Kong have hope and happiness, " she said.