By Roy Ramos

ZAMBOANGA CITY, Philippines

 Two Korean-made fighter jets were delivered to a former major U.S. base in the Philippines’ north Saturday as the archipelago aims to boost its defense system amid tensions over the South China Sea.

A deep roar signaled the arrival of the supersonic FA-50s as they performed two high-speed fly-bys over the Clark Air Base in Angeles City before landing amid applause from air force personnel and reporters, the Philippine News Agency (PNA) reported.

"We’re glad we’re finally back to supersonic age," the state-run agency quoted Department of National Defense Secretary Voltaire Gazmin as saying.

The country’s air force had lacked supersonic aircraft – which can fly faster than the speed of sound, or 750 miles per hour -- since 2005 when it had to decommission its aging Northrop F-5 “Tiger” fighter jets due to lack of spare parts.

The two FA-50s that arrived Saturday are the first of a dozen the defense department ordered from Korea Aerospace Industries on March 2014 under a P18.9 billion ($401.6 million) contract.

The FA-50 has a top speed of Mach 1.5, or 990 miles per hour, and the capacity to carry air-to-air missiles, according to the department’s information sheet.

The PNA reported that the aircraft will serve as the Philippines’ interim fighter until additional funds are raised for fighter jets and air force personnel gain more experience.

The Philippines is pushing its military modernization program as it confronts internal security problems from armed militant groups across the archipelago, as well as China’s perceived “aggression” in disputed waters of the South China Sea -- which Manila calls the West Philippine Sea.

China claims almost all the resource-rich sea, and has overlapping claims with the Philippines, Vietnam, Malaysia, Taiwan and Brunei.

Its reclamation work, which includes the building of airfields on some of the disputed islands, has stirred global controversy and provoked tensions in the region.

The U.S. and its allies have expressed alarm at China's maritime expansion, which they suspect is aimed at extending its military reach, with the Philippines even taking the quarrel to the International Tribunal for the Law of the Sea in The Hague.