Vice foreign ministerial-level officials of Japan, the United States and South Korea have agreed to closely cooperate to enhance regional deterrence of North Korea's missile threat.

Japan's Vice Foreign Minister Mori Takeo spoke by phone with US Deputy Secretary of State Wendy Sherman and South Korean First Vice Foreign Minister Cho Hyun-dong on Monday.

Their discussion followed a recent series of ballistic missile launches by North Korea, including what may have been an intercontinental ballistic missile.

The three diplomats condemned the frequent launches as a grave and imminent threat to regional security, and a clear and serious challenge to the international community.

They confirmed the three countries will continue their close cooperation to strengthen regional deterrence and take steps in the UN Security Council to push for the denuclearization of North Korea in line with UNSC resolutions.

They also agreed to continue trilateral communications at various levels.