South Korea has decided to delay its F-X fighter jet acquisition by a year due to budget constraints.

The third-phase acquisition of 40 to 60 F-X advanced stealth aircraft was originally scheduled to start in 2011, with a final contract in 2012, according to the Korea Times.

The first two stages obtained 60 F-15K aircraft, which were built by Boeing.

The delay will lead to the signing of a contract in 2013 and delivery of aircraft will start after 2016.

The move has disappointed the air force since it had previously planned to replace its 250 McDonnell Douglas F-4Es and Northrop F-5 E/F with the new F-X fighter jet.

The country had planned to indigenously develop 200 KF-X fighters, similar to the US F-16, in cooperation with foreign partners.