The late AMIA bombing prosecutor's ex-wife asked Francis during the brief audience to "keep praying to find the truth" of Nisman's still-mysterious shooting death.
There will be a demonstration in Buenos Aires on Wednesday, the second anniversary of Nisman's death, in front of the AMIA special prosecutors unit, and in Israel with a tribute in the Knesset and a tribute in the coastal city of Nahariya.
The appeals court in Buenos Aires cleared the path to a criminal probe into Cristina Kirchner's motives in cooperating with Tehran on the investigation of the 1994 bombing of the AMIA Jewish center.