BEIJING: China's Foreign Minister Wang Yi said the Philippines' case against China at an arbitration tribunal over rival claims in the South China Sea had strained relations between Beijing and Manila, and that it was up to the Philippines to improve ties.

The arbitration case against China "is a knot that has impeded the improvement and development of Sino-Philippine relations", a statement on the foreign ministry's website cited Wang as saying in Manila.

"We do not want this knot to become tighter and tighter, so that it even becomes a dead knot," Wang, who was in the Philippines for bilateral talks on Tuesday, told reporters in Manila. "As for how to loosen or open the knot, (we'll) have to look at the Philippines."

Beijing claims sovereignty over almost the entire South China Sea, dismissing claims to parts of it from Vietnam, the Philippines, Taiwan, Malaysia and Brunei. For years, China has insisted that disputes with rival claimants to the South China Sea be handled bilaterally.

In a legal setback for Beijing, an arbitration court in the Netherlands ruled late last month that it had jurisdiction to hear some territorial claims the Philippines had filed against China over disputed areas in the South China Sea. The Philippine government has welcomed the decision.

China has boycotted the proceedings and rejects the court's authority in the case.

Manila filed the case in 2013 to seek a ruling on its right to exploit the South China Sea waters in its 200-nautical mile exclusive economic zone (EEZ) as allowed under the United Nations Convention on the Law of the Sea (UNCLOS).

"The person who caused the problem should solve it," Wang said. "We hope that the Philippines can make a more sensible choice."