From the beginning, the German government repeatedly asked Molotov whether the Soviet Union would keep to its side of the partition bargain. The Soviet forces were holding fast along their designated invasion points pending finalization of the five-month-long undeclared war with Japan in the Far East, successful end of the conflict for the Soviet Union, which occurred in the Battles of Khalkhin Gol. On 15 September 1939, Molotov and Shigenori Tōgō completed their agreement that ended the conflict, and the Nomonhan ceasefire went into effect on 16 September 1939. Now cleared of any "second front" threat from the Japanese, Soviet Premier Joseph Stalin ordered his forces into Poland on 17 September. It was agreed that the Soviets would relinquish its interest in the territories between the new border and Warsaw in exchange for inclusion of Lithuania in the Soviet "zone of interest".