Senior officials from Japan, the United States and South Korea plan to discuss North Korea’s nuclear and missile programs this month in Washington, Japanese sources said Thursday.

The move follows an agreement in late March by three leaders to increase trilateral coordination over North Korea, especially after Pyongyang launched two medium-range ballistic missiles into the Sea of Japan last week and has threatened to conduct a “new form of nuclear test.”

The meeting will bring together Junichi Ihara, director general of the Foreign Ministry’s Asian and Oceanian Affairs Bureau, Glyn Davies, U.S. special representative for North Korea policy, and South Korea’s special representative for Korean Peninsula peace and security affairs. That post has been vacant since Cho Tae-yong was promoted to first vice foreign minister in late February. Seoul is expected to name Cho’s successor this week, according to Yonhap News Agency.