German President Frank-Walter Steinmeier has recalled the Second World War as a “German crime” that his nation will never forget during commemorations in Warsaw marking the start of the conflict 80 years ago.

The observances were being led by Polish President Andrzej Duda and also attended by U.S. Vice-President Mike Pence and German Chancellor Angela MerkelU.S. President Donald Trump was originally scheduled to attend but cancelled, citing the need to be home with a hurricane approaching.

Nazi Germany attacked Poland on Sept. 1, 1939, triggering a nearly six-year war that killed more than 70 million people.

Steinmeier called it a “painful legacy” as he recalled the German attack on Warsaw and Poland. He recalled that under the Nazi plan for Poland, “its culture, its cities, its people — everything living was supposed to be destroyed.”

A man in Warsaw wears a Second World War military uniform to commemorate the 80th anniversary of the outbreak of the war. (Omar Marques/Getty Images)

As Duda opened the main commemorations, Polish soldiers sang the national anthem and raised the flag at Warsaw’s Pilsudski Square, a vast space in the centre of the city that was almost totally razed to the ground by the German forces.

The ceremonies in Warsaw follow commemorations in the early hours of Sunday at the exact time of attacks on Poland, in Wielun and on the Westerplatte Peninsula in Gdansk.

Polish Prime Minister Mateusz Morawiecki said during ceremonies at the Westerplatte Peninsula on the Baltic coast, where the war’s first battle was fought that the war “meant not only fire for the Polish homes, it meant the death of Poland’s hopes, Poland’s future, the end of Poland’s science, Polish universities, Polish factories.”

“For this reason we should talk about these losses, we should …. demand redress,” he said.

Poland’s nationalist government has been raising the issue of reparations from Germany ever since it took power in 2015. Germany says that matter is closed.

German President Frank-Walter Steinmeier speaks in Warsaw during a memorial ceremony marking the 80th anniversary of the start of the Second World War. (The Associated Press)