Following a private agreement at the Tehran Conference , confirmed at the 1945 Yalta Conference , the Allied leaders Franklin Roosevelt , Winston Churchill , and Stalin issued a statement affirming the use of the Curzon Line , with some five-to-eight-kilometre variations , as the eastern border between Poland and the Soviet Union . When Churchill proposed to add parts of East Galicia , including the city of Lviv , to Poland 's territory ( following Line B ) , Stalin argued that the Soviet Union could not demand less territory for itself than the British Government had reconfirmed previously several times . The Allied arrangement involved compensation for this loss via the incorporation of formerly German areas ( the so-called Recovered Territories ) into Poland . As a result , the current border between Poland and the countries of Belarus and Ukraine is an approximation of the Curzon Line
Yalta Conference
Yalta Conference
Curzon Line