TOKYO — Saying that his nation will play a larger role in regional security, Prime Minister Shinzo Abe of Japan said on Friday that his government would support Vietnam and other nations that have territorial disputes with China by providing patrol ships, training and military surveillance equipment.

Mr. Abe, speaking at an international security meeting in Singapore, said he wanted Japan to shed the passiveness that has marked its diplomacy after World War II and take more responsibility for maintaining regional stability. He said Japan would cooperate with the United States and other like-minded nations like Australia and India to uphold international rule of law and freedom of navigation, and to discourage China’s increasingly assertive efforts to take control of islands and expanses of ocean that are claimed by other Asian nations, including Japan.

“Japan intends to play an even greater and more proactive role than it has until now in making peace in Asia and the world something more certain,” Mr. Abe said.