Abe will deliver a keynote speech Friday at the Asia Security Summit in Singapore, known as the Shangri-La Dialogue, becoming a first Japanese leader to do so at the gathering. Security is a sensitive topic for Japan, once an aggressor in Asia, to discuss in the region.

Abe said he will make clear China's one-sided maritime and military activities are unacceptable. He will also try to outline his security vision proposing Japan's contribution for regional and global peace.

"I will send a strong message that we will never condone attempts to change status quo by force," he told reporters before departing for Singapore. "I also plan to explain in details what Japan can do to contribute to the Asia-Pacific region and the world" under Japan's new diplomatic and security strategy.

China's moves to assert its territorial claims in the South China Sea are giving impetus to Abe's hopes to play a bigger role in regional security.

In a tangible sign of Abe's effort to deepen ties with Southeast Asia, Japan is exploring whether to supply patrol boats for Vietnam by using Official Development Aid. Japan has agreed to provide 10 Japanese-made boats to the Philippines.