China voiced firm opposition on Sunday to contents concerning the country in a defense authorization bill approved by the US congress.

The bill contains sections relating to the Diaoyu Islands and Taiwan.

In a written statement, Chinese Foreign Ministry spokeswoman Hua Chunying said, "China is deeply concerned and firmly opposed to the contents concerning China in the 2013 Defense Authorization Act."

Hua said the country holds a clear and consistent position on the Diaoyu Islands issue, reiterating that the island and its affiliated islets have always been the inherent territory of China since ancient times.

She referred the Treaty of Mutual Cooperation and Security between the United States and Japan as a "bilateral arrangement in a specific historical time," noting that such a pact should not harm the interests of any third parties including China, nor be involved in any foreign territorial disputes.

The spokeswoman also pointed out that China is firmly opposed to arms sales to Taiwan by any country, urging the politicians in the US congress to abandon their cold war mentality, adhere to the three Sino-US joint communiques and respect China's key national interests.

"They should do more to facilitate regional peace and stability, and help the stable growth of ties between China and the United States as well as the ones across the Taiwan Strait," Hua added.

The US Senate approved the 2013 Defense Authorization Act with an 81-14 margin.

It contains controversial sections relating to the Diaoyu Islands and arms sales to Taiwan. The two clauses are both written as "sense of Congress," which means they have no binding power over the president.

Section 1281 of the bill said, "it is the sense of Congress that... the president should take steps to address Taiwan's shortfall in fighter aircraft, whether through the sale of F-16 C/D aircraft or other aircraft of similar capability."

Section 1286 said, "it is the sense of Congress that" although the US side takes no position on the ultimate sovereignty of the Diaoyu Islands, it "acknowledges the administration of Japan" over them.