President Yoon Suk Yeol reshuffled senior security officials Friday, bringing in the current ambassador to Russia to replace the Foreign Ministry’s first vice minister and sending the current first vice foreign minister to the US as head of mission.

The move to reallocate key security roles ahead of Yoon’s state visit to the US in late April is the latest fallout from the discord within the administration over deciding on a to-do list at the summit. Last week, Yoon essentially fired the top national security adviser for failing to update him on the latest summit preparations. Yoon’s office did not disclose details over the adviser’s “resignation.”

The two incoming appointees are known for their experience in handling matters involving policy on North Korea.

South Korean Ambassador to Russia Chang ho-jin, set to be the first vice foreign minister, previously worked as an aide to the president and foreign minister. The ambassador had spent most of his career drafting anti-North Korea measures.

First Vice Foreign Minister Cho Hyung-dong, who will lead the Korean delegation in the US, is also versed in North Korean affairs, having served as deputy nuclear envoy for North Korea and minister at the Korean Embassy in the US before the current role.

The Korean ambassador to the US had vacated the position as he left to become Yoon’s national security adviser.