A new security law intended to crack down on dissent took effect in Hong Kong on Saturday amid international fears that it will wipe away freedoms in the China-ruled city and damage its standing as an international financial center, according to a report.

The law, known as Article 23, was passed unanimously this week by pro-Beijing lawmakers in Hong Kong who fast-tracked the legislation to close up national security weaknesses.

The law "accomplished a historic mission, living up to the trust placed in us by the Central (Chinese) Authorities," Hong Kong Chief Executive John Lee said, according to Reuters.

Under the new legislation, closed-door trials are authorized, police can detain suspects for up to 16 days without charge. The definitions of espionage and state secrets have been expanded and the penalties for violating them increased.

Secretary of State Antony Blinken in a statement said Article 23 would harm human rights and jeopardize Americans who live and work in Hong Kong.

"This law will have broad implications for the people in Hong Kong as well as U.S. citizens and companies operating there and threatens to further undermine the rights and freedoms of people in Hong Kong," he said.

"It includes vaguely defined provisions regarding 'sedition,' 'state secrets,' and interactions with foreign entities that could be used to curb dissent," he continued.

Australia and Britain also blasted the law during a bilateral meeting in Australia, saying they have "deep concerns about the continuing systemic erosion of autonomy, freedoms and rights," Reuters reported.

The United Nations and the European Union have also criticized the law.

"It is alarming that such consequential legislation was rushed through the legislature through an accelerated process, in spite of serious concerns raised about the incompatibility of many of its provisions with international human rights law,"  United Nations High Commissioner for Human Rights Volker Turk in a statement.