State Border of Ukraine (Ukrainian: Державний кордон України, Derzhavnyi Kordon Ukrayiny, for brevity - DerzhKordon) is an international boundary of the state territory of Ukraine. According to the Article 1 of the Law of Ukraine on the State Border it is a line and a vertical surface that stretches along that line, which define the boundary of territory of Ukraine over the land, water, and air space.