By Venus Wu

HONG KONG (Reuters) - The top U.S. diplomat in Hong Kong on Tuesday described as "unfortunate" Beijing's perceived interference last year, saying in a speech it had undermined public confidence in the territory's autonomy.

The former British colony, governed by China since 1997 under a "one country, two systems" formula that grants it a high degree of autonomy, was rocked last year by controversies that critics saw as signs of a squeeze by Beijing on its freedoms.

The year began with the disappearance of five Hong Kong booksellers, among them two British and Swedish passport holders, who were widely believed to have been abducted by Chinese security and held in custody on the mainland.

In November, China's parliament intervened in a Hong Kong court case that ultimately disqualified two pro-independence lawmakers for failing to take an official oath, by passing a ruling on the city's mini-constitution during the hearings.

"The unwarranted disappearance of the booksellers, as well as the unfortunate, preemptive interpretation of the Basic Law by the National People's Congress with respect to official oath-taking, have contributed to a sense among many in Hong Kong that Beijing may be losing sight of the importance of respecting Hong Kong's autonomy," Kurt W. Tong said in some of his strongest public comments since taking over as U.S. consul general five months ago.

The remarks came a day after the Hong Kong Bar Association kicked off the legal year with a warning that political expedience "must not be given precedence over the rule of law," referring to Beijing's intervention.

Tong, added, however, that he remained "hopeful" Beijing would respect Hong Kong's autonomy, urging Hong Kong residents to go ahead and tackle various issues of the day, and "spend less time worrying about what Beijing thinks".

Ten days before Donald Trump is inaugurated, Tong said he did not expect any major shift in the U.S.-China relationship, despite the U.S. president-elect's often critical Twitter remarks about China's economic, military and foreign policies.

"Overall, I would tend to expect more consistency than inconsistency in our approaches to the region, and that includes Hong Kong," Tong said of the incoming administration.

(This version of the story has been refiled to insert the envoy's dropped first name in paragraph 5)

(Reporting by Venus Wu and James Pomfret; Editing by Clarence Fernandez)