The U.S. subprime mortgage problem had not brought any systematic impact to Hong Kong's banking sector, said the top financial official of the Hong Kong Special Administrative Region (HKSAR) government on Thursday.

John Tsang, financial secretary of the HKSAR government, made the remarks in Beijing where he is paying a two-day visit, and his remarks were quoted by a statement from the HKSAR government.

Noting local market transactions were in order, he said that the interbank market operated smoothly and orderly and that the Hong Kong dollar exchange rate remained stable.

Hong Kong stocks closed at 20,672 points Thursday, down 703 points or 3.29 percent. Tsang said that the plunge was mainly due to a number of external factors, including global market conditions and the U.S. subprime mortgage problem.

He noted that Hong Kong's financial system is capable of handling market volatility, but urged shareholders to act according to their ability and be aware of fluctuating market conditions.

"The Government and financial institutions are monitoring the markets," he said, adding that the Hong Kong Monetary Authority had reviewed information submitted by local banks and found the U.S. subprime mortgage problem had not brought any systematic impact to the sector.