WASHINGTON (AP) — China on Thursday accused the U.S.-allied Philippines of "political provocation" in seeking international arbitration over territorial claims in the South China Sea.

Chinese Foreign Minister Wang Yi said the decision by Philippine leaders to lodge a case with a tribunal in The Hague was "irresponsible to the Filipino people and the future of the Philippines."

China has refused to participate in the proceedings. A ruling is expected later this year, after the tribunal decided last October that it could hear the case.

The Philippines initiated arbitration in early 2013 after Beijing refused to withdraw its ships from a disputed shoal under a U.S.-brokered deal. It contends that China's massive territorial claims in the strategic waters do not conform with the 1982 U.N. Convention on the Law of the Sea and should be declared invalid. The Philippines also asserts that some Chinese-occupied reefs and shoals do not generate, or create a claim to, territorial waters.

Wang blamed the Philippines for shutting the door to negotiations with China over their dispute and seeking arbitration without China's consent.

He said China was prepared to negotiate "tomorrow."

"We are neighbors just separated by a narrow body of water," Wang told the Center for Strategic and International Studies think tank. "We want to contribute to the Philippines' economic development."

Wang was in Washington this week for talks with his counterpart, Secretary of State John Kerry. Differences over the South China Sea have strained U.S.-China relations. The U.S. accuses China of militarizing a key conduit for world trade. China says Washington and its allies are responsible for raising tensions.

China has conducted a massive program of land reclamation over the past two years in the South China Sea, where Brunei, Malaysia, Taiwan and Vietnam also have claims.

Adm. Harry Harris Jr., commander of U.S. forces in the Pacific, told Congress this week that China has constructed more than 3,000 acres (1,210 hectares) of artificial land there in little more than two years, compared with about 115 acres reclaimed by the other claimants in more than 45 years.

Wang said China has stopped reclaiming land but other countries are continuing.

Wang also said China's military facilities on islands and reefs are needed for self-defense as other nations have already militarized surrounding shores. China also intends to build civilian infrastructure like weather stations and emergency harbors for ships in danger, he said, which would benefit the international community.