Pope Leo blasted leaders who spend billions on wars and said the world was “being ravaged by a handful of tyrants”, in unusually forceful remarks in Cameroon on Thursday after US President Donald Trump attacked him again on social media.

Leo, the first US pope, also decried leaders who used religious language to justify wars and urged a “decisive change of course” in a meeting in the biggest city ‌in Cameroon’s anglophone regions, where a simmering conflict going back nearly a decade has left thousands dead.

“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 pontiff said.

“They 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.”

Trump’s attacks on Leo, first launched on the eve of the pope’s ambitious four-country tour of Africa and repeated late on Tuesday, have caused dismay in Africa, where more than a fifth of the world’s Catholics live.

Leo, ⁠who kept a relatively low profile for most of his first year as leader of the 1.4-billion-member Church, has emerged as an outspoken critic of the war that began with US-Israeli strikes ‌on Iran.