Hong Kong stocks opened sharply lower on Thursday, with US lawmakers still at loggerheads over lifting the country's debt ceiling to avert a default and Fitch warning the standoff could trigger a ratings downgrade.

The Hang Seng Index fell almost one percent to 18,930.

The Shanghai Composite Index slipped 0.2 percent to 3,197, while the Shenzhen Composite Index on China's second exchange eased 0.1 percent to 2,007. (AFP)