Much of Asia suffered under Japanese occupation in World War II and its leaders have been wary of a potential resurgence of Japanese militarism.
Japan has been stepping up economic cooperation and investment across Southeast Asia, especially since 2012, when anti-Japanese riots flared in China after Tokyo nationalized a group of uninhabited islands in the East China Sea that are also claimed by Beijing.
As the world's third-largest economy, Japan also plays a crucial role in Asian finance.
On Friday, Tokyo agreed to expand currency swaps and other arrangements with Indonesia and the Philippines that are meant to help stabilize Asian financial markets. Japan also renewed a swap agreement with Singapore, the Finance Ministry said.
In the first six months of this year, Japanese investment in Southeast Asia jumped 89 percent to nearly 1 trillion yen ($9.7 billion) and automakers and electronics companies expanded their factories in the region.