The European Union warned China it could take "additional steps" as it condemned a vote by Beijing's rubber-stamp parliament for sweeping changes to Hong Kong's electoral system.
"The National People's Congress of the People's Republic of China adopted today a decision that will have a significant impact on democratic accountability and political pluralism in Hong Kong," EU foreign policy chief Josep Borrell said in a statement on behalf of the 27-nation bloc.
Thursday's vote includes powers to veto candidates running in the city as Beijing moves decisively to dismantle Hong Kong's democratic pillars after huge protests in the financial hub.
"The European Union regrets that the fundamental freedoms, democratic principles and the political pluralism that are central to Hong Kong's identity and prosperity are under increasing pressure by the authorities," the statement said.
"The European Union calls on the Chinese and the Hong Kong authorities to restore confidence in Hong Kong's democratic process and to end the persecution of those who promote democratic values."
Brussels has previously decided to limit exports of equipment that could be used for surveillance in Hong Kong and EU foreign ministers have discussed the possibility of broader sanctions if the situation worsens.
Foreign ministers meeting last month agreed to increase support to civil society in Hong Kong and step up coordination with international partners to pressure China.
"In light of this most recent decision, the European Union will consider taking additional steps and pay increased attention to the situation in Hong Kong as part of the overall relations between the European Union and China," Borrell's statement said.
