Vatican City - Pope Benedict XVI on Thursday delivered an impassioned defence of Pope Pius XII's World War II record, but stopped short of indicating if or when he will approve the controversial pontiff's path towards sainthood.

Benedict celebrated a Mass in St Peter's Basilica commemorating the 50th anniversary of the death of Pius, who some accuse of having failed to speak out against the Nazi massacre of the Jews.

In his homily Benedict recalled how Pius, in the 1930s before becoming pope had "identified the danger posed by the monstrous National Socialist (Nazi) ideology with its pernicious anti-Semitic and anti-Catholic roots."

The German-born pontiff also rejected charges that Pius had remained silent during the Holocaust.

"How can one forget his Christmas radio message in December 1942, when, with a voice broken by emotion, he deplored the situation of 'hundreds of thousands of people, who through no fault of their own, and sometimes only because of their nationality or origin are destined to die or progressively waste away'?" Benedict said quoting Pius.

Pius "clearly referred to the deportation and extermination perpetrated against the Jews," the pontiff said.

Pius' attempts to save Jews had been acknowledged by many in the Jewish world, including former Israeli prime minister Golda Meir, who, said Benedict, mourned the pontiff's death in 1958 by describing him as "a great servant of peace."

Benedict ended his homily by inviting the faithful to pray for the success of the cause to have Pius beatified - a step towards Roman Catholic sainthood.

In May 2007 the Vatican's saint-making department said it favoured having Pius declared beatified. However, Benedict, has yet to sign the decree authorizing this, "believing a time for reflection is opportune," the Vatican said.

On Thursday, papal spokesman Father Federico Lombardi, said Benedict's homily "explicitly manifested his spiritual union to a widely shared hope of the People of God," to have Pius beatified.

But Lombardi told reporters he could not say whether Benedict would sign the decree nor provide any time-frame.

On Monday, the first Jewish holy man to address the Vatican Synod - a gathering of Roman Catholic Bishops from around the world - caused possible embarrassment to his hosts when in his speech he appeared to criticize Pius.

"We remember those religious leaders who did not raise their voice to save our brethren. We cannot forgive and forget," Rabbi Shear-Yashuv Cohen said.

The Vatican has repeatedly defended Italian-born Pius XII - who reigned from 1939 until his death - citing his instructions that Jews be sheltered from the Nazis in Catholic homes, hospitals, convents and monasteries.

This behind-the-scenes approach, Pius' supporters argue, managed to avoid provoking further Nazi action that would have worsened the situation. (dpa)