U.S. Special Representative for North Korea Stephen Bosworth will wrap up his four-day trip to South Korea on Monday.

During his stay in Seoul, the former U.S. ambassador to South Korea met with top government officials dealing with North Korea’s nuclear issue. Discussions were held on ways to reopen the six-way nuclear talks and ways to ease tensions surrounding the Korean Peninsula.

Bosworth warned that the North will face consequences if it conducts a follow-up to its 2006 nuclear test, a move analysts say the North could soon pursue. However, he also said that the North’s actions cannot be controlled.

Bosworth is scheduled to arrive in Japan on Monday for discussions on ways to resume the nuclear negotiations.

Following talks in Tokyo, special envoy for the six-party discussions, Sung Kim, who is accompanying Bosworth, will travel to Russia to continue consultations.