AboutUS Department of DefenseArticles by US Department Aug. 25, 2017, 4:13 pm US Department of Defense: Mattis, Poroshenko conduct news conference (VIDEO) Nov. 22, 2014, 9:36 am US Department of Defense: US delivers radar systems to Ukraine Aug. 5, 2014, 11:10 pm US Department of Defense: US team arrives in Ukraine for MH17 investigation