Hong Kong’s political heavyweights on Thursday denounced the United States’ signing of a Hong Kong-related bill into law, saying it’s a gross intervention into China’s internal affairs.

Tam Yiu-chung, a Hong Kong deputy to the National People's Congress Standing Committee, the nation’s top legislature, said that by signing the bill, the US has used Hong Kong as a pawn to contain China, which will bring no good to the city and increase its economic uncertainty.

He also blamed the opposition’s role in fueling the situation. Earlier, some opposition politicians went to the US to lobby support for the bill.

Noting that disputes won’t benefit any side, Tam expressed the hope that the Sino-US trade relation could return to normal and not drag Hong Kong into the disputes.

Henry Tang Ying-yen, a Hong Kong member of the Standing Committee of the National Committee of the Chinese People’s Political Consultative Conference, the nation’s top political advisory body, voiced contempt to the US move.

He said the US had used a double standard in handling foreign relations with other countries and urged the US politicians to focus on their own affairs.

The bill’s signing also drew condemnation from the city’s pro-establishment camp. In a Thursday press conference, Martin Liao Cheung Kong, convener of pro-establishment lawmakers, said the formulating process of the bill is full of prejudice and against the principle of democracy and human rights.

Considering the close economic ties between Hong Kong and the US, the bill will not only hurt the interest of Hong Kong people, but also the US, Liao noted.

Democratic Alliance for the Betterment and Progress of Hong Kong, the largest political party in the city’s legislature, said in a Thursday statement that the bill’s signing is a blatant act of hegemonism.

The party urged the US government to stop intervening in Hong Kong affairs and pragmatically advance the economic ties with Hong Kong.

In another statement on Thursday, the Hong Kong Federation of Trade Unions, the city’s largest party representing labor’s welfare, pointed out that the US attempts to take advantage of the recent unrest and interfere with Hong Kong’s internal affairs, which is definitely unacceptable.

Noting the bill will help fuel the ongoing unrest of Hong Kong, the federation urged the US to respect the “one country, two system” principle and the high degree of autonomy of Hong Kong. US politicians should stop ruining Hong Kong’s future by meddling with its own affairs, the statement reads.

Former chief executive of the Hong Kong Special Administrative Region Leung Chun-ying said whoever initiated the act, whether American or Hong Kong people, never had the interest of Hong Kong in mind.

"I don't think the US congressmen who voted for the act were fully or correctly informed. It's a proxy thing. I don't think they had Hong Kong's freedoms, democracy and human rights in mind. It's all about China," Leung said.