The country's first homegrown fighter jet called KF-21 is unveiled during its rollout ceremony in Sacheon, South Korea, April 9, 2021. South Korea on Friday unveiled the first prototype of the KF-X fighter jet it is developing with Indonesia, amid lingering uncertainty over the future of Jakarta's role in the project. Yonhap via REUTERS

The country's first homegrown fighter jet called KF-21 is unveiled during its rollout ceremony in Sacheon, South Korea, April 9, 2021. The next-generation aircraft being developed by Korea Aerospace Industries Ltd (KAI) is designed to be a cheaper, less-stealthy alternative to the U.S.-built F-35, on which Seoul relies. Yonhap via REUTERS

South Korean President Moon Jae-in delivers his speech in front of a prototype of the country's first homegrown fighter jet called KF-21 during its rollout ceremony in Sacheon, South Korea, April 9, 2021. The display at the KAI headquarters in the southern city of Sacheon in a ceremony was attended by South Korean President Moon Jae-in and representatives from Indonesia, including Defence Minister Prabowo Subianto. Yonhap via REUTERS

Indonesian Defense Minister Prabowo Subianto is greeted by South Korean Defense Minister Suh Wook during their meeting at the Defense Ministry in Seoul, South Korea, April 8, 2021. Prabowo discussed the issue with Foreign Minister Chung Eui-yong in Seoul, with both sides agreeing to hold high-level talks about security cooperation, including the KF-X project, South Korea's foreign ministry said in a statement, without elaborating on the cost dispute. REUTERS/Kim Hong-Ji/Pool

Indonesian Defense Minister Prabowo Subianto and South Korean Defense Minister Suh Wook attend a meeting at the Defense Ministry in Seoul, South Korea, April 8, 2021. REUTERS/Kim Hong-Ji/Pool

Indonesian Defense Minister Prabowo Subianto and South Korean Defense Minister Suh Wook pose for photographs during their meeting at the Defense Ministry in Seoul, South Korea, April 8, 2021. REUTERS/Kim Hong-Ji/Pool