The Chinese Foreign Ministry has rejected criticism from Britain and the United States on Hong Kong affairs.
British Prime Minister David Cameron said on Wednesday that Britain should stand up for the rights of people in Hong Kong, Reuters reported.
Speaking in parliament, Cameron said it was important people in Hong Kong could enjoy freedoms and rights set out in the Sino-British Joint Declaration of 1984 that agreed to return Hong Kong to Chinese sovereignty.
He was speaking after protesters in Hong Kong clashed with police early on Wednesday morning.
Foreign Ministry spokesman Hong Lei said on Thursday that the rights and freedoms of Hong Kong residents have been fully guaranteed since Hong Kong returned to China in 1997.
Hong Kong's democratic institutions will achieve historic progress if the island promotes constitutional development in accordance with the Basic Law and the decision of the National People's Congress Standing Committee's (NPCSC), he said.
The NPCSC has decided that the election of a chief executive for the Hong Kong Special Administrative Region (HKSAR) in 2017 shall be implemented by universal suffrage on the basis of nomination by a "broadly representative" committee.
Hong said that Hong Kong's affairs fall within China's internal affairs and no country or individual has a right to interfere.
In Washington, U.S. State Department spokeswoman Jen Psaki said on Wednesday that the United States was concerned by reports of the police actions and urged a "swift, transparent and complete investigation."
In response, Hong said the protesters had blocked main traffic thoroughfares, obstructed law enforcement and severely interfered with the social order in Hong Kong.
Hong Kong's police said they arrested 45 people on Wednesday morning as they cleared Lung Wo Road in Admiralty. Thirty-seven men and eight women were detained for illegal assembly and obstructing the police.
There were chaotic scenes during the clear-out operation as officers scuffled with demonstrators, wrestled some to the ground and forced others off the road. The police had to fire pepper spray during the violence.
No society can tolerate such illegal activities, Hong said, adding that the Hong Kong government has begun investigating the incident.