<Tr> <Td> <Ul> <Li> </Li> <Li> </Li> <Li> </Li> </Ul> </Td> </Tr> <Ul> <Li> </Li> <Li> </Li> <Li> </Li> </Ul> <P> The Molotov--Ribbentrop Pact, also known as the Nazi--Soviet Pact, the German--Soviet Non-aggression Pact or the Nazi German - Soviet Pact of Aggression (officially: Treaty of Non-aggression between Germany and the Union of Soviet Socialist Republics), was a neutrality pact between Nazi Germany and the Soviet Union signed in Moscow on 23 August 1939 by foreign ministers Joachim von Ribbentrop and Vyacheslav Molotov, respectively . The pact was followed by the German - Soviet Commercial Agreement in February 1940 . </P> <P> The pact delineated the spheres of interest between the two powers, confirmed by the supplementary protocol of the German--Soviet Frontier Treaty amended after the joint invasion of Poland . It remained in force for nearly two years, until the German government of Adolf Hitler ended the pact by launching an attack on the Soviet positions in Eastern Poland during Operation Barbarossa on 22 June 1941 . </P>

When did germany and soviet union sign non aggression pact