BEIJING, Dec. 19-- China on Friday expressed resolute opposition after U.S. President Barack Obama signed a bill into law authorizing the sale of Perry-class guided missile frigates to Taiwan.

"The bill seriously violates the three China-U.S. joint communiques, particularly the U.S. commitments specified in the August 17 Communique," said Foreign Ministry spokesman Qin Gang at a daily press briefing.

"It brutally interferes with China's internal affairs, sabotages China's sovereignty and security interests, and runs counter to the trend of peaceful development of relations across the Taiwan Strait," Qin said.

Qin said the Taiwan issue concerns China's core interests and has always been the most important and sensitive issue in China-U.S. relations.

China's firm opposition to U.S. arms sales to Taiwan is resolute, clear and consistent, he said.

"China expresses strong dissatisfaction and firm opposition to this and has lodged solemn representations with the United States both in Beijing and Washington. We reserve the right to take further action," he said.

The United States agreed to gradually reduce arms sales to Taiwan under the August 17 Communique signed in 1982.

Qin urged the U.S. government to abide by the one-China policy and the three China-U.S. joint communiques, stop official and military exchanges with Taiwan, stop arms sales to Taiwan and do more to contribute to China-U.S. relations and the peaceful development of cross-Strait ties.