MANILA (REUTERS) - The Philippines has filed a protest against China's test flights on an artificial island in the South China Sea, a Foreign Ministry spokesman said on Wednesday (Jan 13), describing the actions as "provocative" and a violation of an existing informal code.

Last week, Beijing landed three flights on Fiery Cross in the disputed Spratly archipelago, angering Vietnam and drawing criticism from the United States, which expresssed deep concern it will exacerbate tension in the region.

"We formally protested on Jan 8 the recent test flights by China to Kagitingan Reef," Mr Charles Jose told reporters, using the local name for Fiery Cross Reef, saying the Foreign Ministry summoned China's embassy official to hand over the protest.

Mr Jose said the test flights were "provocative actions" that will restrict the freedom of navigation and overflights in the South China Sea.

Every year more than US$5 trillion (S$7.1 trillion) of world trade is shipped through the South China Sea, believed to have huge deposits of oil and gas, which China claims almost entirely. Brunei, Malaysia, the Philippines, Taiwan and Vietnam have rival claims.

"These actions by China have elevated tensions and anxiety in the region and are in violation of the spirit and letter of the Asean-China Declaration on the Conduct of parties in the South China Sea," he added.

Since 2010, China and the 10-member Asean have been negotiating a legally binding code of conduct to replace the informal rules contained in a political declaration made in Phnom Penh in 2002.

In Washington, foreign and defence ministers of both the Philippines and the United States held talks on trade and security issues, including the US Navy's plan to hold more freedom of navigation patrols in the South China Sea.

US ships and planes will have longer time to patrol the disputed sea because they were given access to Philippine naval and air bases under a new military deal, which the Supreme Court allowed in a decision made on Tuesday.

US Secretary of State John Kerry and Defence Secretary Ash Carter welcomed the court's decision as both Philippine and US military began discussions on a dozen possible locations in its former colony where American ships and planes will have access.

The Enhanced Defence Cooperation Agreement will also allow the United States to build facilities to store equipment and supplies for humanitarian and maritime security operations.