A Chinese marine surveillance ship conducts patrol mission in waters of the South China Sea, file photo. [Photo/Xinhua]

Beijing's position 'remains unchanged', but Philippines broke agreement, spokesman says

China accused the United States on Friday of playing the "arbitrator outside the tribunal" card over disputes in the South China Sea, in response to recent remarks by a top US official that backed the Philippines.

A United Nations arbitration tribunal has been asked by the Philippines to rule on the dispute.

"Attempting to push forward the arbitration unilaterally initiated by the Philippines, the US side acts like an 'arbitrator outside the tribunal', designating the direction the tribunal should take. This is inconsistent with the position the US side claims to uphold on issues concerning the South China Sea disputes," Foreign Ministry Spokesman Lu Kang said in a written statement on Friday afternoon.

"Because it's not a party to the South China Sea issue, the US should live up to its pledge of not taking sides and refrain from actions that go against regional peace and stability," Lu said.

US Assistant Secretary of State for East Asian and Pacific Affairs Daniel Russel said in a speech on Tuesday that arbitration is the only practical means left for China and the Philippines to resolve their competing claims.

The UN Convention on the Law of the Sea, which both have agreed to, requires compulsory dispute settlement, Russel said.

"The United States, of course, is not a party to this arbitration and does not take a position on the merits of the case. But when they became parties to the Convention, both the Philippines and China agreed to its compulsory dispute settlement regime," Russel said in his speech.

Russel also touched on issues concerning China's dotted line boundary in the sea, entitlements to maritime features and the jurisdiction of the arbitration tribunal.