Pope Leo has criticized leaders who spend billions on wars and said the world was being ravaged by a handful of tyrants in unusually forceful comments during a visit to Cameroon.

The pontiff blasted those he said had manipulated the very name of God for their own gain, while touring a region ravaged by a deadly insurgency.

The remarks come just days after a high-profile spat with US President Donald Trump, who posted a lengthy attack on the Pope, a vocal critic of the US-Israeli military operation in Iran.

The Pope had voiced his concern about Trump's threat that a whole civilisation will die if Iran did not agree to US demands to end the war and open the Strait of Hormuz.

Leo, who last year became the first US-born Pope, has previously also questioned the Trump administration's approach to immigration.

Speaking in Cameroon, the Pope criticized leaders who turn a blind eye to the fact that billions of dollars are spent on killing and devastation, yet the resources needed for healing, education and restoration are nowhere to be found.

He expressed that, the masters of war pretend not to know that it takes only a moment to destroy, yet often a lifetime is not enough to rebuild. The Pope also condemned an endless cycle of destabilization and death in a bloodstained region that has been gripped by insurgency for nearly a decade.

Following his address, the Archbishop of Canterbury expressed solidarity with the Pope’s call for peace, while highlighting the urgent need for humanitarian action in light of ongoing conflicts around the world.