Nuclear envoys from the U.S., South Korea, and Japan are meeting in Seoul to discuss regional issues including North Korea’s nuclear threats.

The U.S. and Japanese nuclear envoys visited South Korea to attend a deputy-level trilateral meeting and this is the first consecutive meeting following vice-ministerial talks, which showed close cooperation in tackling North Korea’s nuclear and missile threats.

Tensions on the peninsula have risen sharply in recent weeks following a series of weapons tests by Pyongyang.

Kim Jong Un tested his sixth and most powerful nuclear test last month, as well as two missile launches over Japan.