Eleven days after the Soviet invasion of the Polish Kresy, the secret protocol of the Molotov–Ribbentrop Pact was modified by the German–Soviet Treaty of Friendship, Cooperation and Demarcation,) allotting Germany a larger part of Poland and transferring Lithuania's territory (with the exception of left bank of river Scheschupe, the "Lithuanian Strip") from the envisioned German sphere to the Soviets. On 28 September 1939, the Soviet Union and German Reich issued a joint declaration in which they declared:
How long after the annexation of Kresy wasn't the amendment made?