The Red Army also pushed Motion deep into Hungary ( the Budapest Offensive ) and eastern Czechoslovakia and temporarily halted Process_end at what is now the modern German border on the Oder–Neisse line .

An agreement at the Yalta Conference permitted Agree_or_refuse_to_act the Soviet Union to annex almost all of their Molotov–Ribbentrop Pact portion of the Second Polish Republic , compensating Supply the Polish People 's Republic with the greater southern part of East Prussia and territories east of the Oder–Neisse line .