The head of South Korea's arms procurement agency on Wednesday attended a ceremony in Indonesia to mark the handing over of a 1,400-ton submarine to its navy, his office said.

The 61-meter submarine, dubbed Alugoro, was the third unit South Korea delivered to Indonesia under a 1.3 trillion-won (US$1.15 billion) contract in 2011 to export three submarines to the Southeast Asian country, according to the Defense Acquisition Program Administration.

Daewoo Shipbuilding & Marine Engineering Co. delivered the first two submarines to the Indonesian Navy in 2017 and 2018, and the last unit's main body was delivered to Indonesia earlier for final assembly by local shipbuilder PT PAL.

At the ceremony, the agency chief Kang Eun-ho said the submarine will serve as a new milestone in the two countries' defense cooperation and congratulated Indonesia for becoming the first country among the Association of Southeast Asian Nations (ASEAN) members to have the ability to build a submarine.

Indonesia signed another deal with South Korea in 2019 to purchase three additional submarines, but the project has made little progress since then.

Kang's visit comes amid speculation that Indonesia, also a partner for South Korea's first indigenous fighter jet project, is seeking to quit the business.

The Southeast Asian country promised to shoulder 20 percent of the 8.8 trillion-won development cost, but it has stopped making payments after investing 227.2 billion won with around 600 billion won overdue.

"Kang exchanged opinions with senior Indonesian officials on a broad range of issues related to defense cooperation between the two countries," the agency said in a release. (Yonhap)