The US Senate has approved an amendment to the 2013 National Defense Authorization Act concerning the Diaoyu Islands.

The amendment says the United States takes no position on the ultimate sovereignty of the Diaoyu Islands, but acknowledges Japan's administration over the islands under Article 5 of the US-Japan security treaty.

The amendment also says the unilateral actions of a third party will not affect its position. Chinese Foreign Ministry spokesman Hong Lei responded to the amendment during a routine press conference on Monday.

Hong Lei, Spokesman, Chinese Foreign Ministry, said, "China expresses its serious concern and firm objection to the U.S. Senate's amendment to the 2013 National Defense Authorization Act...We hope the US will bear in mind the broader interests of peace and stability in the region, honor its word with actions, and refrain from sending self-contradictory signals."