Indonesia this week opened a military base with over 1,000 personnel on a remote island at the southern edge of the disputed South China Sea, most of which is claimed by China.

The base that opened Tuesday is on Natuna Besar Island, located in the middle of the Natuna Islands situated between Borneo and the Malay Peninsula, more than a thousand kilometers from Jakarta

In a speech at the base, Indonesian Defense Force chief, Marshal Hadi Tjahjanto, said the outpost is designed to work as a deterrent against any potential security threats, particularly in border areas, according to military spokesman Col. Sus Taibur Rahman.

Before the base inauguration, the islands only had an unsophisticated airbase and a small naval base, which were not integrated with each other.

The military chief said the new base at Selat Lama, the island’s major port, has a hangar for an unmanned aerial vehicle squadron. The base, he said, will be improved in accordance with threat levels, while the personnel there are prepared to join in any military operation.

Hadi did not disclose the exact number of military personnel available in the Natuna Islands area, but said the new base is supported by an army battalion, companions of engineers and marines as well as artilleries.

In Indonesia’s military, a battalion consists of between 825 and 1,000 personnel, while a companion consists of around 100 personnel.

“The development of this kind of military base will also be done in other strategic islands…,” he said without elaborating.

Last year, the Indonesian government unveiled an updated national map in which the country’s exclusive economic zone north of the Natuna Islands was renamed the North Natuna Sea. It was previously described as being part of the South China Sea.

In 2002, Indonesia renamed the section of the South China Sea within its EEZ as the Natuna Sea, except for the waters north of the Natuna Islands. With the latest name change, the South China Sea is no longer used for any part of Indonesia’s territorial waters.

While China recognizes Indonesian sovereignty over the Natuna Islands, it insists the two countries have overlapping claims to maritime rights and interests in the area that need to be resolved — a claim that Indonesia rejects.

“When (such) a claim was voiced…I was really upset. I brought a warship to Natuna. If you want us to fight, together we will do it,” President Joko Widodo, who prefers to be known as “Jokowi,” told Muslim leaders on Madura Island, off the northern coast of Java Island, on Wednesday, alluding to incidents in 2016.

At that time, some Chinese fishing boats were caught by the Indonesian authorities for operating illegally in the country’s exclusive economic zone in Natuna Sea, with Beijing declaring the Natuna area to be “a traditional fishing ground” for Chinese vessels.

Immediately after the name change, China expressed opposition to the move, saying changing an internationally accepted name complicates and expands the dispute, affects peace and stability and will not be conducive for the peaceful bilateral relations.

Indonesia countered, however, that it had the right to name its territorial waters and the North Natuna Sea falls within its territory.

In the South China Sea, home to some of the world’s busiest sea lanes, China has overlapping territorial claims with the Philippines, Vietnam, Malaysia and Brunei, as well as Taiwan.