In January 1944, Soviet troops had reached the former Polish–Soviet border, and by the end of July 1944 they again re-annexed the whole territory that had been taken by the USSR in September 1939 into their control. During the Tehran Conference in 1943, a new Soviet-Polish border was established, in effect sanctioning most of the Soviet territorial acquisitions of September 1939 (except for some areas around Białystok and Przemyśl), ignoring protests from the Polish government-in-exile in London. The Potsdam Conference, via substantive recognition of the pro-Soviet Polish Committee of National Liberation, implicitly consented to the deportation of Polish people from Kresy (see Polish population transfers (1944–1946)).