Lockheed Martin will supply 40 F-35 fighter jets to South Korea after military chiefs settled a drawn-out tender process today.
The first delivery is expected in 2018, after a Joint Chiefs of Staff meeting agreed that the country would be best served by buying warplanes with the most advanced stealth technology and electronic warfare capability.
The meeting of top brass modified required capabilities for a stronger deterrence against rival North Korea, who they technically remain at war with, but the decision still needs to be put to a committee chaired by the defence minister for final approval.
"What fits into modified requirement operational capabilities is limited to that model," said defence ministry spokesman Kim Min-seok when asked if the military would choose the F-35 given the revised requirements.
Lockheed Martin welcomed the news and said it remained committed to a package of technology transfers and other projects to satisfy Korea's offset requirements, despite a cut in the number of jets to be ordered.
The offset package includes a new military communications satellite, support for South Korean efforts to develop a new KF-X fighter jet, and a cyber-warfare training centre.
"We put a bunch of projects on the table and we're not backing away," Randy Howard, Lockheed's South Korea F-35 campaign director, told Reuters in a telephone interview. "I'm confident we can find a way to preserve the projects that have been offered."
South Korea was initially expected to give the greenlight to Boeing's F-15 Silent Eagle, as the aircraft was the only one among three fighter jets in the race to fall within Seoul's budget. Under South Korean law, only bids on or under budget are considered.
But in September, South Korea decided to re-examine the terms of the 8.3tn Korean won (£48.2bn) tender to buy 60 fighter jets after rejecting Boeing's bid.
At the time, South Korea mentioned its need for an advanced, radar-evading jet, later mirrored by the Air Force asking for enhanced technological requirements for the jets and bolstering Lockheed's chances with the F-35.
Boeing said in a statement it remained confident its F-15, "with its superior speed, range and payload, combined with cost and schedule certainty, is what Korea needs to meet its defence needs and address the growing fighter gap".
Officials with the third bidder, Europe's Eurofighter were not immediately available for comment.
South Korea's shift toward the F-35 has been influenced by Japan's decision to order the stealth fighter and China's development of indigenous stealth fighters, according to experts, due to concerns that not having stealth jets would result in a major capability gap between its neighbours.
"One of the biggest reasons this programme was first envisioned was to strengthen the air force's power as nearby nations announced their plans to adopt stealth fighter jets," said Kim Jong-ha, dean of the Graduate School of National Defense & Strategy at Hannam University.
The remaining 20 fighter jets to be acquired by South Korea will be open to various models, defence ministry spokesman Kim said, and are expected to be delivered from 2023.
Given the renewed process, the military and the finance ministry will redesign the budget size, officials said.
"We expect to firm up the total budget size after discussions with the related ministry," said Oh Tae-shik, a senior official at the country's arms procurement agency.
Analysts say that as the delivery for a further 20 warplanes is still a decade away, South Korea will likely seek an even more advanced jet than the F-35.