MANILA (AFP) - The Philippines has ordered two new warships from South Korea's Hyundai Heavy Industries, Defence Secretary Delfin Lorenzana said on Tuesday (Dec 28), modernising Manila's navy as it faces a dispute with Beijing in the South China Sea.

The Philippine Navy had become run down in recent decades - even featuring United States craft from World War II - until President Rodrigo Duterte's predecessor, Mr Benigno Aquino, began a modest modernisation programme in 2010.

Tuesday's 28 billion peso (S$751 million) deal with the South Korean shipbuilding giant comes five years after the firm also won a contract to build two frigates for the Philippine Navy.

Corvettes and frigates are small, fast warships mainly used to protect other vessels from attack.

"This project will give the Philippine Navy two modern corvettes that are capable of anti-ship, anti-submarine and anti-air warfare missions," Mr Lorenzana said in a speech at the signing ceremony in Manila.

The deal "will ensure commonality and interoperability with our existing assets", he added, as well as "ease of maintenance and repairs".

Manila has acquired two former US Coast Guard cutters and three landing craft from Australia, as well as coast guard patrol vessels from Japan, in an effort to bolster its presence in the South China Sea, where it faces a dispute with Beijing.

China claims almost all of the waterway, through which trillions of dollars in trade pass annually, with competing claims from Brunei, Malaysia, the Philippines, Taiwan and Vietnam.

Beijing has ignored a 2016 ruling by The Hague-based Permanent Court of Arbitration that its historical claim is without basis.