German Chancellor Angela Merkel, Russian Prime Minister Vladimir Putin, and 20 other European leaders attended the main ceremony to commemorate the attack on a military garrison at the Westerplatte peninsula off Gdansk.

As part of the ceremony, hosted by Polish President Lech Kaczynski and Prime Minister Donald Tusk, the leaders placed candles at the Cemetery of Defenders of Westerplatte.

Merkel: " I bow to the victims"

Speaking at the site, Chancellor Merkel said no country had suffered under German occupation as much as Poland.

"The war unleashed by Germany resulted in immeasurable suffering to many peoples - years of deprivation of rights, of humiliation and destruction," she said.

"I bow to the victims. We know the horrors of the Second World War, they cannot be undone. The scars remain. But the future is our responsibility. “

She also described the post-war reconciliation that has led to Europe living in freedom and peace as a 'miracle.'

All pacts with Nazis in 1934-39 "morally inacceptable"

In his address, Prime Minister Putin avoided the issue of the Red Army's invasion, but he said it was time to stop putting all the blame on the Molotov-Ribbentrop Pact. Under the terms of that agreement, Germany and the Soviet Union agreed to divide Poland up between them.

Putin added that all agreements by various countries aimed at appeasing the Nazis were "morally unacceptable, politically senseless, harmful and dangerous."

After the Nazis tore up their non-aggression pact with Moscow in 1941 and invaded Russia, Soviet forces found themselves fighting against the Germans.

“The number of deaths was terrible,” Putin said. “Out of 50 million people who died in World War II, over half were citizens of the USSR.”

Poland remembers aggression by two major powers

Although September 1, 2009 marks the start of World War II, Poland is not just remembering German aggression, but also Russia's invasion on September 17.

That invasion, “was like a "knife in the back," Polish President Kaczynski said earlier in the day, during pre-dawn ceremonies to mark the moment the first shots were fired.

In his afternoon address, the Polish president said the commemorations were not simply about remembering the war.

“Two generations have passed since this war. Everyone should ask what caused it. It was totalitarianism, nationalism and chauvinism."

"Today, we understand the importance of freedom, democracy and pluralism. Secondly, there has been a resignation of imperialist dreams, a partial resignation of totalitarianism and dictatorships," he said.

"Without this, we would not have a united Europe, and that is why today we have 27 countries, and I believe in the future, something that will be completely new."

wl/AP/AFP/Reuters/dpa

Editor: Chuck Penfold