His trip comes amid apparent friction between the allies over how to enforce global sanctions imposed on North Korea amid almost stalled denuclearization talks.

South Korea has been eager to expand cross-border exchanges, which have been blocked by sanctions on Pyongyang. The US has said that sanctions will remain in place until the North completely gives up its nuclear weapons program.

Joint projects between South and North Korea, such as railway and road connections over their border, have been faced with apparent opposition from the US On Monday, the two Koreas held a meeting but failed to produce dates for joint surveys of their roads, which are needed for their connection as agreed upon in a summit in April.

Cho will likely emphasize Seoul's argument that an improvement in inter-Korean relations could benefit the denuclearization process and ask the US to cooperate in easing sanctions on key cross-border projects.

During his five-day stay, Cho is also expected to meet Rep. Ed Royce, chairman of the House Foreign Affairs Committee, and visit the Center for Strategic and International Studies and other institutes to meet local experts on North Korea.

This marks the first time in about four years for South Korea's incumbent unification minister in charge of North Korea issues to visit Washington. (Yonhap)