Indonesia will now refer to the northern areas of its exclusive economic zone in the South China Sea as the "North Natuna Sea" in an act of defiance against Beijing's territorial ambitions in the region, the media reported.
At a press conference in Jakarta on 15 July, Deputy Minister for Marine Sovereignty Arif Havas Oegroseno unveiled a new map with the renamed territory, reports CNN.
"We need to continue updating the naming of the sea and report to the UN about the borders," Oegroseno told Indonesia's state-run news agency Antara.
"This (system) would allow the international community to know whose territory they pass through," he added.
Part of the renamed area falls in China's "nine-dash line" -- waters extending hundreds of miles to the south and east of China's island province Hainan.
China claims the entirety of the sea, but Vietnam, Taiwan, the Philippines, Brunei and Malaysia all have competing territorial claims to parts that are near their respective shores, reports CNN.
Indonesia is not the first country to rename part of the South China Sea.
In 2011, the Philippines renamed the waters as the "West Philippine Sea" and two years later took the territorial dispute before an international tribunal at The Hague.
In July 2016, the tribunal ruled in favour of the Philippines, concluding that China has no legal basis to claim historic rights to the bulk of the South China Sea.
China responded by calling the ruling a farce..