The Pope has reportedly been warned he's at risk of an assassination attempt by Islamic State extremists when he visits a Muslim-majority country this weekend.

The Telegraph newspaper reports that the Vatican has been warned of the credible threats to Pope Francis' life as he prepares to visit Albania.

Iraq's ambassador to the Holy See says the pontiff could also be vulnerable when he travels to Turkey in November.

"What has been declared by the self-declared Islamic State is clear – they want to kill the Pope. The threats against the Pope are credible," the ambassador told La Nazione, an Italian daily, on Tuesday.

"I believe they could try to kill him during one of his overseas trips or even in Rome. There are members of Isil who are not Arabs but Canadian, American, French, British, also Italians.

"Isil could engage any of these to commit a terrorist attack in Europe."

Jihadis from I.S. have in recent weeks bragged about planting their black flag on top of St Peter's Basilica.