HONG KONG, Sept. 6 (Xinhua) -- The government of China's Hong Kong Special Administrative Region (HKSAR) on Friday refuted Fitch's downgrade of Hong Kong's credit rating and stressed the "one country, two systems" principle is the foundation of Hong Kong's sustained prosperity.

The HKSAR government disagreed and was disappointed with Fitch's decision of downgrade, said Paul Chan, financial secretary of the HKSAR government.

The credit-rating agency downgraded Hong Kong's sovereign rating from AA+ to AA and the outlook from stable to negative, saying "months of persistent conflict and violence are testing the perimeters and pliability of the 'one country, two systems' framework."

Chan said the social incidents over the recent months have not affected Hong Kong's core competitiveness, and the Basic Law has strongly safeguarded the "one country, two systems" principle and the continued prosperity of Hong Kong since its return to the motherland.

"The HKSAR government remains committed to upholding the 'one country, two systems' principle and the Basic Law, which are the most important and solid foundation for Hong Kong's sustainable social and economic development," Chan said.