
U.S. Secretary of State Rex Tillerson (L) and British Foreign Secretary Boris Johnson attend a family photo session during a NATO Foreign Ministers meeting at its headquarters in Brussels, Belgium, March 31, 2017.(Xinhua/Ye Pingfan)

U.S. Secretary of State Rex Tillerson (L) and British Foreign Secretary Boris Johnson attend a family photo session during a NATO Foreign Ministers meeting at its headquarters in Brussels, Belgium, March 31, 2017.(Xinhua/Ye Pingfan)