MANILA » The Chinese and Philippine defense chiefs warned rival claimants Monday to avoid unilateral action and focus on responsible behavior in disputed South China Sea islands, where recent spats have renewed tensions.

Chinese Defense Minister Liang Guanglie and his Philippine counterpart, Voltaire Gazmin, acknowledged in a joint statement the need to ensure that the South China Sea remains stable and called for "responsible behavior" while claimant nations seek a peaceful solution.

Liang’s four-day visit comes amid renewed tensions in the disputed Spratly Islands, which are contested by China, the Philippines and four other nations.

Washington has expressed concerns that the disputes could hamper access to one of the world’s busiest commercial sea lanes.

"Unilateral actions which could cause alarm should be avoided," the defense ministers said in the statement.

Gazmin said they discussed the May 11 sighting of two unidentified foreign fighter jets near an island occupied by Filipino troops that drew Philippine government concerns. Two Philippine patrol planes failed to identify the jets, which were at a higher altitude and made no hostile moves.

Liang, according to Gazmin, mentioned that Philippine media accounts identified the two aircraft as Russian-made MIG fighter jets and clarified that China has no MIG planes in its air force.

The discussions did not touch on a March 2 incident in which the Philippine government accused two Chinese patrol boats of harassing a Filipino oil exploration ship into leaving a vast area called the Reed Bank. A Filipino general scrambled two military aircraft, which arrived at the scene after the Chinese vessels had left, the Philippine military said.

China and the Philippines have swapped diplomatic protests. Filipino officials say the Reed Bank, which lies off the western Philippine province of Palawan, is not a disputed territory. China countered by saying that it has jurisdiction over the Spratlys and adjacent waters.

Gazmin said he and Liang agreed that any conflict "should be settled amicably by opening the lines of communication, dialogues and sitting down and talking to each other."

The 10-member Association of Southeast Asian Nations, which includes the Philippines and three other countries that claim the Spratlys, signed a nonbinding accord with China in 2002 that discourages aggressive behavior.

Liang and Gazmin said the accord was useful but expressed hope that China and ASEAN could resolve a long-standing disagreement that has prevented them from finalizing the guidelines under the 2002 accord that would allow claimants to undertake joint, confidence-building projects in the disputed areas.

Philippine President Benigno Aquino III said he intended to raise the territorial disputes in a meeting with Liang later Monday. "The end point is hopefully these incidents could be reduced, otherwise a conflict might really happen," Aquino said Sunday.