As a consequence of the Molotov–Ribbentrop Pact, on September 17, 1939, the Kresy territories were annexed by the Soviet Union (see Soviet invasion of Poland), and a significant part of the ethnic Polish population of Kresy was deported to other areas of the Soviet Union including Siberia and Kazakhstan.[13] The new border between Nazi Germany and the Soviet Union was re-designated by the German–Soviet Frontier Treaty, signed on September 29, 1939.