
U.S. Secretary of Defense Mark Esper attends a NATO defense ministers meeting at the NATO headquarters in Brussels, Belgium, Feb. 13, 2020. The two-day NATO defense ministers meeting closed on Thursday. (Xinhua/Zhang Cheng)

U.S. Secretary of Defense Mark Esper attends a NATO defense ministers meeting at the NATO headquarters in Brussels, Belgium, Feb. 13, 2020. The two-day NATO defense ministers meeting closed on Thursday. (Xinhua/Zhang Cheng)