In February 1945 , American and British officials met in Yalta and agreed on the basics on Poland 's future borders . In the east , the British agreed to the Curzon line but recognised that the US might push for Lwów to be included in post-war Poland . In the west , Poland should receive part of East Prussia , Danzig , the eastern tip of Pomerania and Upper Silesia . President Franklin D. Roosevelt said that it would " make it easier for me at home " if Stalin were generous to Poland with respect to Poland 's eastern frontiers . Winston Churchill said a Soviet concession on that point would be admired as " a gesture of magnanimity " and declared that , with respect to Poland 's post-war government , the British would " never be content with a solution which did not leave Poland a free and independent state . " With respect to Poland 's western frontiers , Stalin noted that the Polish Prime Minister in exile , Stanisław Mikołajczyk , had been pleased when Stalin had told him Poland would be granted Stettin/Szczecin and the German territories east of the Western Neisse . Yalta was the first time that the Soviets openly declared support for a German-Polish frontier on the Western as opposed to the Eastern Neisse . Churchill objected to the Western Neisse frontier , saying that " it would be a pity to stuff the Polish goose so full of German food that it got indigestion . " He added that many Britons would be shocked if such large numbers of Germans were driven out of these areas , to which Stalin responded that " many Germans " had " already fled before the Red Army . " Poland 's western frontier was ultimately left to be decided at the Potsdam Conference
Potsdam Conference
Potsdam Conference
Oder–Neisse line