Unification minister Lee In-young called for the resumption of inter-Korean cooperation at the Han River estuary on Wednesday, visiting the border region amid an extended delay in joint research projects in the area.

The Han River flows through Seoul but meets the West Sea near the border with North Korea. While the Korean War (1950-1953) armistice agreement states that the estuary “shall be open to civil shipping of both sides,” continued military confrontation has barred the free movement of civil vessels along the riverway.