Pope Francis will meet the senior leader of world's Sunni Muslims at the Vatican this Monday.

No immediate information about the important agenda to be discussed by the two church leaders is available, but sources said it includes, among others, filling the gap between Islam and Christian for peace, and the crisis in Syria and Iraq.

Sheikh Ahmed al-Tayeb, the grand imam of Cairo's prestigious institution Al-Azhar University,  is a critic to Islam extremism, and was the first Muslim leader to criticize the terrorist attack in Paris saying 'terrorism was not an expression of any Abrahamic faith. It was rather an "intellectual and psychological disease" that uses religion as a front.

Father Federico Lombardi, the pontiff's spokesman, said, "This audience is being prepared and has been scheduled for Monday. It will be a first."

Relations between Vatican and the Muslims soured when then Pope Benedict XVI was perceived to have tagged Islam as the religion of violence. The crack was patched up when Francis took over and made inter-faith dialogue top of his agenda.

Pope Francis and the imam shared impartiality in religious practices that an individual should have absolute freedom to practice his religious belief.

Tayeb had met the Archbishop of Canterbury at Lambeth Palace. Both stressed their common commitment to building "bridges of peace."

Last February 2015, al-Tayeb had also called for the reform of Islamic teaching saying: there had been "a historical accumulation of excessive trends" that had led some people to embrace a misguided form of Islam."

He said one of the factors that has rendered Islamic State's brand of ideology so toxic is the habit of pronouncing other Muslims as apostates.

Referring to the terrorist groups who have opted for savage and barbaric practices, .Al-Tayeb said: the only hope for the Muslim nations to recover unity is to tackle in schools and universities this tendency to accuse fellow Muslims of being unbelievers.