HONG KONG, July 1 (Xinhua) -- Lam Cheng Yuet-ngor was sworn in Saturday morning as the Chief Executive of the Hong Kong Special Administrative Region (HKSAR), as Hong Kong marks the 20th anniversary of its return to China.

Lam took her oath before President Xi Jinping, who oversaw the swearing-in ceremony. The president shook hands with Lam after the oath taking.

Then, the principal officials of the fifth-term HKSAR government also took their oaths before Xi.

Members of the Executive Council of the HKSAR were sworn in by Lam.

"It is with a humble heart that I accept this greatest honor of my life and prepare to take on the greatest challenge in my public service career," Lam said in her inauguration speech.

Lam said she will "resolutely do everything" within her ability to implement the "one country, two systems" principle, uphold the Basic Law of the HKSAR and defend the rule of law.

"As we capitalise on our strengths and harness the opportunities presented by our country's development, Hong Kong's future is indeed bright and promising," Lam said.