UN envoy to Yemen Martin Griffiths (2nd L) shakes hands with Yemen's President Abdu-Rabbu Mansour Hadi in Aden, Yemen, on July 10, 2018. The United Nations special envoy for Yemen arrived Tuesday in the southern port city of Aden to discuss ongoing peace efforts with President Abdu-Rabbu Mansour Hadi. (Xinhua/Ismail Rabidhy)