South Korean Prime Minister Lee Nak-yon (C) poses for a photo with Kim Yong Nam (3rd L), president of the Presidium of the Supreme People's Assembly of the Democratic People's Republic of Korea (DPRK), and Kim Yo Jong (3rd R), the younger sister of top DPRK leader Kim Jong Un, in Seoul, capital of South Korea, on Feb. 11, 2018. (Xinhua/Newsis)