At the Tehran Conference of 1943, Stalin, Roosevelt and Churchill issued the Tehran Declaration that guaranteed the post-war independence and boundaries of Iran. However, when the war actually ended, Soviet troops stationed in northwestern Iran not only refused to withdraw but backed revolts that established short-lived, pro-Soviet separatist national states in the northern regions of Azerbaijan and Iranian Kurdistan, the Azerbaijan People's Government and the Republic of Kurdistan respectively, in late 1945. Soviet troops did not withdraw from Iran proper until May 1946 after receiving a promise of oil concessions. The Soviet republics in the north were soon overthrown and the oil concessions were revoked.