A trip to the Holy Land by Pope Benedict could help overcome "prejudice and incomprehension" marking Catholic-Jewish relations, a senior Vatican official said.

The Vatican is exploring the possibility of Benedict making his first trip to Israel and the Palestinian territories since his election in 2005. The Vatican has said the visit is still possible, despite the latest violence in Gaza.

Cardinal Walter Kasper, in charge of relations with Jews, acknowledged that "problems haven't been lacking" in Catholic-Jewish ties, including outrage over a prayer that some saw as calling for the conversion of Jews.

He also pointed to recent tensions over the role of wartime Pope Pius XII, who some Jews have accused of turning a blind eye to the Holocaust.

"I'm convinced then that the pope's hoped-for trip to the Holy Land would be decisive to overcome prejudice and incomprehension that mark our relations with Judaism," Kasper told Vatican newspaper L'Osservatore Romano.

The Church says Pius worked quietly behind the scenes to help Jews during the Holocaust and that the re-introduction of the prayer in question did not indicate a change in the Church's high regard for Jews or its contempt for anti-Semitism.

"The Jewish world has understood and accepted that (Pius') beatification is an internal process of the Catholic Church," Kasper said.

Many Jewish groups have called on Benedict to freeze the process that could one day make Pius a saint until more Vatican archives on the wartime period are opened.

"We trust now that historic research will bring even more clarity about the Pius XII's work to help Jews during the years in question," Kasper said.