SEONGNAM, South Korea, June 14 (Yonhap) -- North Korea is expected to take measures to denuclearize within the next two to three weeks following this week's historic summit between Washington and Pyongyang in Singapore, an expert on North Korea said Thursday. Former Unification Minister Lee Jong-seok, currently a senior researcher at the private think tank Sejong Institute, made the remark during a forum hosted by the institute in Seongnam, just south of Seoul, to analyze the outcome of the Tuesday summit between U.S. President Donald Trump and North Korean leader Kim Jong-un. Lee also took a view that the United...