
U.S. Secretary of Defense James Mattis leaves the European Council headquarters after EU-USA Leaders' Meeting, in Brussels, Belgium, May 25, 2017. (Xinhua/Ye Pingfan)

U.S. Secretary of Defense James Mattis leaves the European Council headquarters after EU-USA Leaders' Meeting, in Brussels, Belgium, May 25, 2017. (Xinhua/Ye Pingfan)