Indonesia said it will sign a defense agreement with Japan -- a move certain to raise concerns in China, with which Jakarta already has a military pact.
Indonesia on Friday announced that a non-binding defense agreement will be signed with Japan next week when President Joko Widodo visits Tokyo for talks with Prime Minister Shinzo Abe.
Indonesian officials say the agreement will increase cooperation in military technology, training and peacekeeping operations; a significant boost above their current defense relationship, which is essentially limited to the exchange of military students. The new pact might also include exchanging intelligence information.
Indonesia has enjoyed a more formal military relationship with China -- with which it has a binding agreement -- and has purchased Chinese missiles and other equipment.
President Widodo is also to visit China immediately after Japan.
Foreign Ministry spokesman Armanatha Nasir said the president will raise the contentious South China Sea territorial dispute in both Tokyo and Beijing.
"Of course the issue of regional peace and stability will be discussed both in Japan and China, because the importance of ensuring that the region continues to benefit from stability and peace, because this is a major factor in the contribution for the region's economic development," Nasir said.
Japan does not have claims in the South China Sea, but it and China do dispute the sovereignty of uninhabited islands in the East China Sea, which are controlled by Japan.
Indonesia, the largest country in Southeast Asia in terms of size and population, has taken a neutral stance on territorial disputes, as Nasir points out, offering itself as a broker to its neighbors and China.
"We're a non-claimant country, but we're committed to helping ensure that there can be trust within the countries, claimant countries, on this issue," noted Nasir. "We have pushed for the negotiation through ASEAN in particular, and I think there's certain progress there where China and the other claimants who are ASEAN members have been discussing this issue."
Under Prime Minister Abe, Japan has bolstered its security policy, increasing ties with the Philippines and Vietnam, which also have territorial disputes with China.
Closer military ties with Jakarta would make the Japanese defense industry more competitive with South Korean manufacturers of military equipment.
At home, Abe has sought to loosen restrictions contained in Japan's pacifist constitution imposed on it by the United States after the Japanese defeat in the Second World War. But that has caused considerable anxiety in China and on the Korean peninsula, which suffered at the hands of Japan's colonialism in the first half of the 20th century.