South Korea Seeks to Blunt Skepticism of Its Outreach With North

SEOUL—South Korea’s president said his country would stick with tough economic sanctions against North Korea until “real progress” is made toward ending its nuclear-weapons programs, in an attempt to blunt skepticism over Seoul’s efforts to kick-start dialogue between Washington and Pyongyang.

On Tuesday, South Korean officials who met with Kim Jong Un said the North Korean leader had expressed a willingness to negotiate with the U.S. and signaled an openness to abandoning nuclear weapons in exchange for security guarantees....