U.S. Secretary of State Rex Tillerson (R) and Secretary of Defense James Mattis attend a press briefing after the U.S.-China Diplomatic and Security Dialogue in Washington D.C., the United States, on June 21, 2017. China and the United States began their first diplomatic and security dialogue on Wednesday at the U.S. State Department in Washington D.C. (Xinhua/Yin bogu)
