Melbourne: In a boost to South Korea’s air power amidst tension with North Korea, the US State Department has approved a $5.06 billion sale of 25 F-35A fighter jets for South Korea. The Defence Security Cooperation Agency on September 13 announced the possible deal, which could change in quantity and contract value during the negotiations process.

The potential sale, which now goes to Congress for consideration, would also include 26 Pratt & Whitney F135-PW-100 engines for the aircraft, an upgrade to the Block 4 standard, as well as cryptographic appliques and electronic warfare support. If approved, the sale will bring South Korea’s fleet to 65 F-35A conventional-takeoff-and-landing aircraft. The country’s Air Force is currently in the process of taking delivery of 40 F-35As it previously ordered to equip its 17th Fighter Wing at Cheongju.

South Korea is using its F-35As to replace it fleet of McDonnell Douglas F-4E Phantom II fighter jets. It had previously considered buying the F-35B short-takeoff-and-vertical-landing variant to equip its planned aircraft carrier.

However, the Defence Ministry said earlier this year it is looking at the feasibility of building a 50,000-ton aircraft carrier, which is considerably larger than originally planned. Such a ship would enable the South Koreans to operate catapult-launched carrier aircraft instead of the F-35B. This would likely be a naval version of the locally designed Korea Aerospace Industries KF-21 Boramae fighter. South Korea’s defence acquisition agency concluded in January that developing a carrier borne KF-21 was feasible within a 10-year time frame.

South Korea is technically still at war with its nuclear-armed neighbour North Korea, as the two countries have not signed a formal peace treaty following the 1953 armistice that ended the Korean War.