National Security Adviser Wi Sung‑lac said Thursday that South Korea and the United States had agreed to move quickly on follow‑up measures to agreements reached at their recent summit.

In a phone interview with Yonhap News TV after a two‑day visit to Washington, Wi described consultations with U.S. officials as positive and showing progress, though he said it was difficult to cite specific achievements.

He said both sides had pledged to promptly implement the items in the joint fact sheet issued after the South Korea-U.S. summit.

The document mentions U.S. support for South Korea’s civilian uranium enrichment and reprocessing of spent nuclear fuel, as well as Washington’s approval of Seoul’s plan to build nuclear‑powered submarines.

Wi, who arrived in Washington on Tuesday, met U.S. Secretary of State Marco Rubio the same day and Energy Secretary Chris Wright on Wednesday.

He is scheduled to travel to New York on Thursday to discuss South Korea–UN relations and issues related to the Korean Peninsula with senior United Nations officials.