European officials have gathered in Warsaw to remember the victims of Stalinism and Nazism on the 72nd anniversary of the signing of a nonaggression pact between Nazi Germany and the Soviet Union.

Known as the Ribbentrop-Molotov Pact, it paved the way for the start of World War II with the German and Soviet troops' 1939 invasion of Poland, dividing the country between them.

Representatives of several European countries met Tuesday to sign a so-called "Warsaw declaration" vowing that the suffering of victims of totalitarian regimes "will not sink into oblivion." The event comes after the European Parliament voted in 2008 to establish 23 August as the European Day of Remembrance for Victims of Stalinism and Nazism to preserve the memory of the victims.