The United States held coordinated sea patrols with both the Philippine and Malaysian navies in the Sulu Sea, where a spate of ship hijackings by Islamist militants happened early this year, officials said on Friday.

U.S. Navy officials said the sea patrols last week were part of multilateral Cooperation Afloat Readiness and Training (CARAT) drills following increased attacks by the Abu Sayyaf on shipping, raising fears the problem could reach levels seen off Somalia.

Rear Admiral Charles Williams, the commander of U.S. Navy Task Force 73, said that he felt the multilateral training taught them important lessons of relationships between the navies and nations.

The multilateral training tested the abilities of all three navies to coordinate maritime security operations in a geographically separated environment at sea.

Williams commented on the upcoming change of government with President-elect Rodrigo Duterte taking office on June 30 and his comment about not relying on the U.S. government to resolve disputes, particularly in the south China Sea.

"So from the U.S. side, I really quite honestly don't have any idea how, I don't have any insights on how the incoming president's policies will matter or will affect what I think is a long history of very successful operations between the Philippine navy and the U.S. Navy. We have not just 22 years, but more than 50 years of very cooperative and very professional engagement between the the two navies and the two countries," he said.

Williams also said there will be no changes in the relationship between the U.S. and the Philippines and the results of the arbitration case filed by the Philippines against China over disputed territories in the South China Sea..

"I think if I understood the question correctly, you were asking about what change and presence we would have. I would just offer to you that the United States has had a persistent and continuous presence in the Western Pacific, as a Pacific nation ourselves for over 70 years. That presence has never wavered, it has only been persistent and sustained, and I would expect it to be just that in the future," Williams said.

The Philippines has lodged a case in The Hague about its dispute with Beijing in the South China Sea, angering China which has pledged not to participate.

China claims most of the South China Sea, which was believed to be rich in natural gas and a valuable shipping lane. Taiwan, Malaysia, Vietnam, the Philippines and Brunei also have competing claims.