“A majority of the committee members agreed to reject [the F-15] and restart the project," Defense Ministry spokesman Kim Min-Seok said, according to Agence France-Presse.
Boeing’s F-15 Silent Eagle is a fourth-generation fighter, lacking some of the stealth capabilities of the fifth-generation F-35 from Lockheed Martin.
“There is a consensus that South Korea needs the fifth-generation fighter jet to deter the growing threat posed by North Korea," Kim said.
Lockheed’s F-35 bid, as well as one from EADS for its Eurofighter Typhoon, had already been rejected for being over-budget.
South Korea said that it would begin the project from scratch and re-assess its budget for the new fighters, according to AFP.
"We believe that the whole review process will take about a year," Kim said. "We will expedite the process to make sure that the void in our national defense will be limited to a minimum.”