The - Pact, also known colloquially as the Hitler-Stalin Pact or German-Soviet Non-aggression Pact or Nazi-Soviet Pact and formally known as the Treaty of Non-aggression between Germany and the Union of Soviet Socialist Republics, was a non-aggression treaty between the German Third Reich and the Soviet Union. It was signed in Moscow on August 24, 1939 - but dated August 23 - by the Soviet foreign minister Vyacheslav and the German foreign minister Joachim von .