Francis' comments to an international conference on anti-Semitism came as the largely Roman Catholic Poland considers legislation that would outlaw blaming Poles for the crimes of the Holocaust. The proposed legislation has sparked an outcry in Israel.
Francis didn't mention the dispute but he did speak of his 2016 visit to the Auschwitz-Birkenau death camp in German-occupied Poland, saying he remembered "the roar of the deafening silence" that the left room for only tears, prayer and requests for forgiveness.
He called for Christians and Jews to build a "common memory" of the Holocaust, saying "it is our responsibility to hand it on in a dignified way to young generations."
"The enemy against which we fight is not only hatred in all of its forms, but even more fundamentally indifference, for it is indifference that paralyzes and impedes us from doing what is right even when we know that it is right," he said.
The anti-Semitism conference, hosted by the Italian foreign ministry in cooperation with the OSCE and Italy's Jewish communities, was timed to correspond to International Holocaust Remembrance Day.
On the eve of the commemoration, Poland's lower house parliament approved a bill calling for prison time for referring to "Polish death camps" and criminalizes the mention of Polish complicity in the Holocaust.
Many Poles believe such phrasing implies that Poles had a role in running the camps. But critics worry it could be used to stifle research and debate on topics that are anathema to Poland's nationalistic authorities, particularly the painful issue of Poles who blackmailed Jews or denounced them to the Nazis during the war.
In his remarks, Francis called for a "culture of responsibility" among nations to establish an "alliance against indifference" about the Holocaust.
"We need urgently to educate young generations to be actively involved in the struggle against hatred and discrimination, but also in overcoming conflicting positions in the past, and never grow tired of seeking out the other," he said.
Quoting his predecessor, Pope John Paul, Francis said everyone should work for a future where "the unspeakable iniquity of the Shoah will never again be possible." Shoah is the Hebrew word for the Holocaust.
Poland, where Auschwitz is located, has also seen acts of anti-Semitism recently.
One, exposed by a television station, showed people in a forest last year chanting "Sieg Heil" on what would have been Adolf Hitler's 128th birthday.
About 60,000 people, some carrying banners with slogans such as "pure blood, clear mind," marched in a far-right demonstration in Warsaw in November and arsonists set fire to a synagogue in Sweden last month.
Ronald Lauder, president of the World Jewish Congress, said: "In country after country, we are watching a growing wave of far-right, ultra-national, and in some cases neo-Nazi parties gaining strength."
Associated Press and Reuters contributed to this report.