The Philippines has invited bids in a Ps6 billion ($23 million) programme to acquire two long range patrol aircraft for the country’s air force.

The bids are to include the cost of the aircraft, sensors, systems integration, as well as support capabilities, according to a document posted on the Department of National Defense’s website.

Manila requires that bids be delivered on before 13 June, with bids received to be opened on that day. Upon reviewing the initial bids, a second bidding stage will be implemented. Manila also requires that bidders have successfully completed a similar process within the last ten years.

The announcement follows recent requests for bids on two other airpower requirements: a Ps5 billion requirement for six close support aircraft for the air force, and Ps5 billion contract for two anti-submarine helicopters for the navy.

The acquisition announcements, with their emphasis on enhancing Manila’s maritime airpower capabilities, come at a time of heightened territorial disputes in the South China Sea, large swathes of which are subject to rival claims by China, Vietnam, the Philippines, Brunei, and Taiwan.

In addition to aircraft, Manila is also looking to bolster its navy through the acquisition of amphibious assault vessels and fast attack craft.

Manila’s push to obtain new equipment follows its decision in March to order 12 Korea Aerospace Industries FA-50 fighter aircraft for $420 million.

The FA-50 announcement marked an important step for Manila, which has no operational fighter aircraft after it retired its Northrop F-5s in 2004. During the 2000s its focus was primarily on counterinsurgency missions in the southern Philippines, but China’s increasing assertiveness in the South China Sea has prompted Manila to rethink its conventional capabilities.

Manila’s airpower capaiblity is negligible. According to Flightglobal’s MiliCAS database, its only armed combat aircraft are eight ageing Rockwell OV-10 close air support aircraft.