The Group of Seven industrialized nations on Monday expressed their "grave concern" over what they view as an erosion of democracy in Hong Kong after pro-Beijing members swept the territory's Legislative Council election.

Chinese and Hong Kong authorities should "restore confidence in Hong Kong's political institutions" and "end the unwarranted oppression of those who promote democratic values and the defense of rights and freedoms," the foreign ministers of the G-7 countries, including the United States and Japan, said in a statement.

The Hong Kong legislative election was held on Sunday without any candidates from the city's major pro-democracy parties following Beijing-led electoral changes aimed at ensuring that only "patriots" govern the city.

The package of changes to the electoral system introduced earlier this year in Hong Kong, including the establishment of a new vetting process that severely restricts which candidates can appear on the ballot, "undermined Hong Kong's high degree of autonomy," the G-7 ministers said.

Under China's "one country, two systems" policy, Hong Kong was promised it would enjoy the rights and freedoms of a semiautonomous region for 50 years after the former British colony's return to Chinese rule in 1997.

But Beijing has been tightening its grip on the territory, such as by enacting what Washington called a "draconian" national security law last year and by imposing the new electoral system in May this year.

"We strongly reiterate our call on China...to...respect fundamental rights and freedoms in Hong Kong," the statement said.

The G-7 groups Britain, Canada, France, Germany, Italy, Japan and the United States as well as the European Union.

A similar statement expressing concern over moves to undermine Hong Kong's rights and freedoms was issued the same day by foreign ministers from the intelligence-sharing alliance known as Five Eyes, a group consisting of Australia, Britain, Canada, New Zealand and the United States.