Which of the following countries was not an axis power during World War II?

The Soviet Union was not an Axis Power during World War II because it entered into a non-aggression pact with Nazi Germany known as the Molotov-Ribbentrop Pact in August 1939. This pact allowed the Soviet Union to annex territories in Eastern Europe and gain time to prepare for a potential conflict with Germany. However, Germany violated the pact and invaded the Soviet Union in June 1941, leading to the Soviet Union joining the Allied Powers to fight against Nazi Germany.