Hong Kong US bill
Pro-democracy protesters gather at the Occupy Central protest site in Admiralty in Hong Kong December 10, 2014. REUTERS/Athit Perawongmetha

WASHINGTON (Reuters) - A bipartisan group of U.S. legislators reintroduced a bill on Friday aimed at putting pressure on China to ensure autonomy and human rights in Hong Kong.

The Hong Kong Human Rights and Democracy Act would update a 1992 law that has afforded Hong Kong trade and economic privileges not enjoyed by mainland China.

It would require the U.S. secretary of state to certify annually that Hong Kong is sufficiently autonomous before enacting any new laws or agreements granting Hong Kong such different treatment. It would also allow the secretary to waive the certification on national security grounds.

The bill was originally introduced last year, but there was not time to process it before the term of the previous Congress expired.

It is sponsored by Republican Representatives Chris Smith and Dana Rohrabacher and Democrats Eliot Engel and Dan Lipinski.

"A status quo U.S. policy is unsustainable if Beijing continues to insist that Hong Kong become like mainland China," Smith said in a statement issued by the four congressmen.

"The special privileges the U.S. grants to Hong Kong can only endure if Beijing fulfills its longstanding obligation under international law to maintain Hong Kong’s autonomy, guarantee human rights and allow free and fair elections in 2017 and beyond."

The statement said that after returning from British to Chinese sovereignty in 1997, Hong was supposed to enjoy a "high degree of autonomy" and freedoms that do not exist in mainland China.

However, it noted that in the past year Beijing had taken steps eroding such autonomy and freedoms, including a decision in August by the National People’s Congress "that raised very serious concerns that only pro-Beijing candidates would be nominated for chief executive in 2017."Given the tens of thousands of Hong Kong people who demonstrated peacefully last year for democratic reforms, the Hong Kong and Chinese governments should seek new proposals for electoral reform," the statement said.

Hong Kong legislators are to vote in late June or early July on whether or not to accept a Beijing proposal that would allow all citizens a vote in the 2017 leadership election but only for candidates pre-screened by a pro-Beijing committee.

Protesters who camped out for two months on the streets of Hong Kong last year and some city legislators oppose the proposal and instead demand full and free democracy.

(This story has been refiled to correct spelling of name in paragraph 5 to Eliot from Elliot)

(Reporting by David Brunnstrom; Editing by Dan Grebler and Christian Plumb)