The new Shah soon signed an agreement pledging full non-military logistical cooperation with the British and Soviets, in exchange for full recognition of his country's independence, and also a promise to withdraw from Iran within six months of the war's conclusion (these assurances later proved essential in securing his country's independence after the war). In September 1943, the Shah went further, and he declared war on Germany. He signed the Declaration by United Nations entitling his country to a seat in the original United Nations. Two months later, he hosted the Tehran Conference between Churchill, Roosevelt, and Stalin.