BEIJING - Hong Kong's new leader Carrie Lam officially accepted her appointment as chief executive Tuesday in Beijing, state media said, after she won an election dismissed as a sham by the region's democracy activists.

The former career civil servant was chosen in late March as the next head of the semi-autonomous city by a mainly pro-China committee, and was widely seen as Beijing's favourite candidate for the post.

It was the first leadership vote since the mass Umbrella Movement rallies in the financial hub in 2014, which called for fully free elections but failed to secure reforms.

Pro-democracy activists said none of the candidates truly represented Hong Kong and rejected the vote outright.

 Lam received an official

certificate of appointment from Chinese premier Li Keqiang at a ceremony in the Zhongnanhai leadership compound, then met with President

Xi Jinping. 

In her 36-year-long career, she had demonstrated "a firm stance in loving the country and Hong Kong, a diligent, pragmatic and responsible work style, as well as rich administrative experience and ability to handle complicated situations," Xi said, according to Xinhua. Hong Kong was handed back to China by colonial ruler Britain in 1997 under a "one country, two systems" formula designed to protect its freedoms and way of life for 50 years. But 20 years on, there are serious concerns Beijing is undermining the agreement.

A Hong Kong technician was jailed for four years and nine months on Monday for rioting and arson during anti-China protests dubbed the "fishball revolution" last year -- the harshest punishment yet over the unrest.

An activist in the 2014 rallies was last month also sentenced to three months in prison, while nine more campaigners face charges. Lam, whose Cantonese name is Lam Cheng Yuet-ngor, pledged to uphold the "one country, two systems" principle in a recent interview with Xinhua, published Tuesday.