MANILA (Reuters) - The Philippines has asked the United States to hold joint naval patrols, a defense ministry spokesman said on Thursday, amid a territorial dispute with China in the South China Sea.

Subi reef, located in the disputed Spratly Islands in the South China Sea, is shown in this handout Center for Strategic and International Studies (CSIS) Asia Maritime Transparency Initiative satellite image taken September 3, 2015 and released to Reuters October 27, 2015. REUTERS/CSIS Asia Maritime Transparency Initiative/DigitalGlobe/Handout via Reuters

Foreign and defense ministers from the United States and the Philippines met in Washington this week for the second time in more than three years to discuss trade and security, focusing on the South China Sea.

“We are suggesting that we also patrol the area together,” Peter Paul Galvez told reporters in Manila. “There is a need for a more collaborative presence in the South China Sea.”

U.S. Navy Secretary Ray Mabus underscored the importance of the U.S.-Philippine relationship, but declined to comment on the Philippine request for joint patrols.

A Pentagon spokesman, Commander Bill Urban, said the United States engaged “in numerous joint defense activities” year round with its ally, including exercises, capacity building, training, and intelligence sharing.

“While we do not comment on our joint planning discussions, we routinely evaluate ways to strengthen and enhance our military cooperation to better meet regional security challenges,” he said.

China claims almost all the disputed South China Sea, where it has built artificial islands that extend its reach. Brunei, Malaysia, Vietnam, Taiwan and the Philippines have competing claims in the sea, through which $5 trillion of trade passes annually.

Speaking at the annual conference of the Surface Navy Association near Washington, Mabus said the U.S. Navy was working closely with the Philippines through joint exercises, prepositioning of supplies and other steps.

A Philippines military spokesman said on Wednesday Manila had offered the United States eight bases where it can build facilities to store equipment and supplies under a new security deal.

Mabus said the accord paves the way for even closer ties, although the next steps were still being discussed.

“They’re a very, very important international partner, and they’re in a very important part of the world,” Mabus said.

Tensions were heightened earlier this month when China began test flights from Fiery Cross Reef, one of three artificial islands where Beijing has built airfields.

The Philippines has challenged Beijing at the arbitration court in The Hague, a case Beijing has not recognized.

The United States has no South China Sea claim and says it takes no sides, though it has been highly critical of China’s assertiveness and says it will protect freedom of navigation.

It carried out a navy patrol near areas claimed by China, Taiwan, Vietnam and the Philippines in October. A U.S. defense official said this month it remained committed to carrying out more but was still debating the timing.