Dozens of Chinese vessels that were fishing in Indonesia's Exclusive Economic Zone off the disputed island of Natuna began leaving the area Jan. 9, after days of stand-off. Indonesia deployed eight warships and four fighter jets to the area in response to the presence of the Chinese vessels, and summoned Beijing's ambassador in Jakarta to complain. A military statement said: "Our Navy and air force are armed and have been deployed to the North Natuna Sea [to] drive out the foreign vessels." China was reported to have sent three coast guard cutters into the area during the stand-off. The Natuna archipelago, off the northwest coast of Borneo, occupies a particularly strategic spot in the South China Sea. Its waters contain significant oil and gas reserves, and it guards the eastern opening of the narrow Malacca Strait, a critical chokepoint for shipping lanes. The archipelago falls within China's "nine-dash line," an area covering nearly the entirety of the South China Sea. 

"We urge China to explain the legal basis and provide clear a definition for its claims on Indonesian EEZ based on 1982 UNCLOS," said a statement from the Indonesia  Ministry of Foreign Affairs, refering to the United Nations Convention on the Law of the Sea.

Amid the stand-off, President Joko "Jokowi" Widodo made a visit to the Natuna Regency, as the archipelago is administratively known. "This visit shows that the Indonesian government, especially the President, is paying serious attention to the issue of Natuna," Cabinet Secretary Pramono Anung said. Pramono cited a similar case in which Jokowi asserted Indonesia's sovereignty in the region in 2016, when the president held a limited Cabinet meeting on board a warship in Natuna waters. (Channel News Asia, News.com.au, SCMP, Jakarta Post)