Indonesia has recently suggested to the Seoul government to cut its share of payment and pay about 600 billion won (US$442.3 million) in total for the KF-21 jet project by 2026, a decrease from the initial 1.6 trillion won, Yonhap news agency reported.

"South Korea and Indonesia are continuing close communication and consultations between relevant authorities to smoothly conclude strategic cooperation projects, such as the joint development of fighter jet," the official told reporters.

In 2016, Indonesia had agreed to pay 20 per cent of the total development cost of 8.1 trillion won, in return for receiving one prototype model and technology transfers that would allow it to produce 48 units in Indonesia.

On Wednesday, Seoul's state procurement agency hinted at accepting Indonesia's proposal, saying that it will finalise its decision as early as late May so as not to cause delays in the development project.

"We are pushing for measures to adjust the scale of the technology transfer to Indonesia in line with the adjusted cost sharing," Noh Ji-man, director general of the Defense Acquisition Program Administration's KF-X Program Group, said in a press briefing.