Berlin  - With a "commitment to peace, to understanding and mutual respect," the Bishops of the Catholic Church in Germany and Poland issued a joint declaration Tuesday in commemoration of the start of the Second World War 70 years ago.

It is imperative that "the post-war generation achieves and preserves an appropriate understanding of the war," a joint-statement issued by the German Bishops' Conference in Bonn and the Polish Bishops Conference in Czestochowa said.

The Second World War is officially marked as beginning on September 1, 1939, when the German army invaded Poland. In the course of the six-year conflict, some 60 million people across the world died.

The statement called on humanity to look forward to the future without forgetting, or underestimating, the reality of history.

The bishops said that in the decades since the end of the war, the process of reconciliation had born fruit, but also that in both countries forces were still at work that would attempt to distort history and stoke resentment.

"The church will confront such misrepresentations of history," said the heads of both Bishops' Conferences, Archbishop Jozef Michalik of the Polish Episcopate and German Archbishop Robert Zollitsch said.

Both churches condemned the crimes of the war, and further urged young people in Germany and Poland to learn each other's language and culture, "to give expression to our common Christian roots."

The reconciliation between our two countries is a gift that we have brought into the unification of Europe," the statement said.

On Sunday, the German and Polish bishops are to hold a joint memorial ceremony in St. Hedwig's cathedral in Berlin, which is to be attended by German President Horst Koehler. (dpa)