The territory of Poland had been completely occupied by the two powers by October 6, and the Polish state was liquidated. In early November the Supreme Soviet of the Soviet Union annexed the occupied territories and the Soviet Union shared a common border with Nazi Germany, the Nazi-occupied Polish territories and Lithuania for the first time. After the invasion, cooperation between Germany and the Soviet Union was visible, for example, in the four Gestapo-NKVD Conferences, where the occupying powers discussed plans for dealing with the Polish resistance movement, for the further destruction of Poland, and which enabled both parties to exchange Polish prisoners of interest prior to the signing of German–Soviet Frontier Treaty in Moscow in the presence of Joseph Stalin.[116][117][118]