Indonesian navy South China Sea
Indonesian President Joko Widodo was accompanied by several top politicians in his visit to Natuna islands Darren Whiteside/Reuters

Indonesian President Joko Widodo has held a top-level cabinet meeting aboard a warship stationed on the volatile waters of the South China Sea, in what appears to be a stern message to Beijing. His visit to the Natuna islands has come amid high tensions and territorial claims and counter-claims in the region.

Widodo was flanked by Chief Security Minister Luhut Panjaitan, Foreign Minister Retno Marsudi and military chief General Gatot Nurmantyo. Several other top ministers also accompanied him during the visit.

The leaders were on board the KRI Imam Bonjol 383 – one of the five warships deployed in the waters off Natuna islands.

The delegates discussed the economic development of Natuna islands – the flashpoint where the Indonesian navy recently confronted more than a dozen Chinese fishing vessels. The islands are strategically located adjacent to Malaysia, Vietnam and Cambodia and the waters off the archipelago are a key trade route.

"In the course of our history, we've never been this stern (with China). This is also to demonstrate that the president is not taking the issue lightly," Luhut told the Jakarta Post.

The Indonesian navy had recently fired on Chinese fishing vessels and captured crew from one of the boats. Jakarta said that none of those detained were hurt. This is the third such encounter between Indonesian forces and Chinese boats in recent months.

Even during the recent encounter between Indonesian navy and Chinese fishermen, Beijing acknowledged that the Natuna belonged to Indonesia. However, with a caveat, it added that some waters of the South China Sea are subject to "overlapping claims on maritime rights and interests" – a remark that sharply angered Indonesia.

Shortly ahead of Widodo's departure to Ranai, the capital of Natuna Regency, Indonesia's Cabinet Secretary Pramono Anung said: "Natuna is Indonesian territory. That is final. As head of government and head of state, the president wants to ensure that Natuna is part of Indonesia's sovereignty."