Historians long clamored for access to the Vatican archives of letters and other documents spanning the years of Pius XII’s 1939-1958 pontificate, which overlapped with World War II.

The chairman of Israel’s Yad Vashem Holocaust memorial said he thanked Pope Francis on Thursday for giving scholars access to the Holy See’s World War II-era archives.

Mr. Dani Dayan, who met with Francis at the Vatican, said the pontiff described the archives’ opening as “an issue of justice.” Francis visited the memorial during a 2014 pilgrimage in Israel.

The Vatican, in its account of the meeting, didn’t say what Francis told his Israeli visitor. But its official media quoted Mr. Dayan’s account of the pontiff’s words.

When I thanked him for opening the archives of the Vatican of the relevant period of the Holocaust for our researchers, he said very clearly that to open the archives is to make justice, Mr. Dayan said.

Over the decades, many have criticized Pius for not speaking out at the time against the mass deportations and systematic murder of Jews. The Vatican has long contended that Pius worked quietly behind the scenes to save lives during the Holocaust.

But scholarly examinations of the wartime archives so far suggest that the people the Vatican worked hardest to save were Jews who had converted to Catholicism or who were children of Catholic-Jewish marriages.

Vatican media quoted Yad Vashem’s Mr. Dayan as saying Francis told him that the Catholic Church isn’t afraid of history.

The Holy Father went on to say that he is well aware that, as in other organizations, in the church there were people who did the right thing and those who did not, Mr. Dayan said.

When visiting Yad Vashem in 2014, the pope prayed before a crypt with ashes of Holocaust victims and laid a wreath of flowers in the Hall of Remembrance.

As Thursday’s meeting concluded, Mr. Dayan invited Francis to again visit Israel and Yad Vashem.

Mr. Dayan told Vatican Radio that the two men, each natives of Buenos Aires, conversed in Spanish, and that Francis was “very clear in condemning anti-Semitism” and in combatting it as an “ally.”