U.S. Secretary of State John Kerry will meet with his Japanese and South Korean counterparts in New York on Sunday to discuss responses to North Korea’s latest nuclear test, South Korea’s foreign ministry said on Wednesday.

The three countries are pushing for tough new U.N. Security Council sanctions on North Korea after the isolated country on Friday conducted its fifth and largest nuclear test.

The blast was in defiance of U.N. sanctions that were tightened in March.

South Korea said Foreign Minister Yun Byung-se and his counterparts Kerry and Japanese Foreign Minister Fumio Kishida will meet during the annual U.N. General Assembly to discuss putting further pressure on North Korea.