TOKYO (AP) — China’s moves to assert its territorial claims in the South China Sea are giving fresh impetus to a Japanese push to play a bigger role in regional security, adding to the growing strains between the two Asian rivals.

Japan said this week it is exploring whether it can accelerate a proposal to supply patrol boats for Vietnam, which is embroiled in a tense standoff at sea with China after Beijing moved an oil rig into disputed waters. In a similar deal, Japan agreed in December to lend 18.7 billion yen ($183 million) to the Philippines to purchase 10 Japanese-made boats.