Iraq’s ambassador to the Vatican Rahman Al-Ameri had said last week that the senior cleric and the head of the Catholic Church will sign the document during the upcoming visit.
The two leaders will also sign a document on human fraternity aimed at promoting mutual trust among followers of all faiths, al-Ameri said.
The document calls for commitment to values like peace, fraternity, peaceful coexistence, justice and benevolence, he added.
The office of Ayatollah Sistani said, however, that there have been no discussions about such a document.
Pope Francis is scheduled to visit Iraq March 5-8 in what would be the first-ever papal trip to the country.
As well as meeting with Iraq’s religious and political leaders, Francis is due to preside over an interfaith meeting in Ur, the birthplace of Prophet Ibraheem (Abraham).
Iraqi Prime Minister Mustafa al-Kadhimi said last week that the Pope’s visit will spread the spirit of brotherhood in Iraq and the region.