Pope Francis on Sunday called on Muslim leaders to issue a global condemnation of terrorism, saying it would help to dispel the stereotype that equates Islam with terror.

Speaking to reporters aboard the plane as he returned from Turkey, Francis said, according to the Reuters news agency, that he made the suggestion in private talks on Friday with the country’s president, Recep Tayyip Erdogan.

“I told the president that it would be beautiful if all Islamic leaders, whether they are political, religious or academic leaders, would speak out clearly and condemn this, because this would help the majority of Muslim people,” Francis said in answer to a reporter’s question.

“But this must come from the mouths of their leaders, from religious leaders, academic leaders, intellectuals and political leaders,” he added.

On Friday, Pope Francis condemned the Islamic State (ISIS) terrorist group and called for interfaith cooperation in order to combat it.

He said that “an extremist and fundamentalist group” had subjected entire communities in Turkey’s southern neighbors to “barbaric violence simply because of their ethnic and religious identity.”

He called for inter-religious dialogue to end of all forms of fundamentalism and terrorism, and stressed the importance of freedom of religion and of expression.

“It is essential that all citizens – Muslim, Jewish and Christian – both in the provision and practice of the law, enjoy the same rights and respect the same duties,” the pope said.

Friday’s call came just days after the Pope called for “dialogue” with the ISIS. Such dialogue is “almost impossible,” conceded the pope, although he said, “I never say ‘all is lost,’ never. Maybe there can’t be a dialogue but you can never shut a door.”

Catholic Church officials have urged Islamic leaders to speak out more forcefully against Islamic State, but the pope’s words on the plane were his most comprehensive so far.

He called for “a global condemnation (of terrorism), including from Muslims, who have their own identity and say ‘we are not that, the Koran is not that’,”.

He said he understood how Muslims were offended by the stereotype that equates Islam with terrorism.

“They say: ‘No, we are not this, the Koran is a book of peace, it is a prophetic book of peace. This is not Islam,’” he said, according to Reuters.

ISIS has made clear that it is waging a war on Christianity, noting that Rome is a key target for conquest as the home of the Vatican and a core symbol of Christianity.

In September, the Vatican had to increase security over intelligence reports of a possible ISIS attack on Pope Francis.