Algiers — Pope Leo has responded to sharply-worded criticism from the President, saying he has "no fear of the Trump administration" and will continue to speak out "loudly" for the message of the Gospel.

Late Sunday, Mr. Trump lashed out at the pontiff on social media, calling him "WEAK on Crime, and terrible for Foreign Policy."

"I don't want a Pope who thinks it's OK for Iran to have a Nuclear Weapon," he added.

Leo had previously called Mr. Trump's threat to wipe out Iranian civilization "truly unacceptable" and encouraged people to contact "political leaders … to ask them, tell them to work for peace."

Speaking to journalists Monday aboard the papal plane as he began a trip to Africa, Leo declined to address the president's post directly. "I am not a politician," he said. "I will leave that to the politicians."

But he pushed back on the substance of Mr. Trump's criticism, warning against attempts to equate his message with political agendas, and hinting that the president did not understand the message of the Gospel. 

"To put my message on the same plane as what the president has attempted to do here is, I think, not understanding what the message of the Gospel is," he said. "I am sorry to hear that, but I will continue with what I believe is the mission of the Church in the world today."

That mission, he said, is rooted in a consistent call for peace, one he insisted applies to all leaders, not just the United States.

"The message of the Gospel is very clear: 'Blessed are the peacemakers,'" Leo said, adding that he will not shy away from proclaiming it. "Too many people are suffering today. Too many innocent people have been killed."

The pope said he sees his role not as entering political debates, but as offering a moral alternative at a time of rising global tensions.

"Someone has to stand up and say that there is a better way," he said, pointing to dialogue, reconciliation and multilateral cooperation as the path forward.

Mr. Trump's post criticizing the pope came just a short time after "60 Minutes" aired a story discussing the pontiff's statements and influence with three American cardinals who know him well. Mr. Trump later confirmed to CBS News senior correspondent Norah O'Donnell that he had watched the show, and that he believes the pontiff is "wrong on the issues."

Leo's remarks come at the start of an 11-day trip that will take him to Algeria, Cameroon, Angola and Equatorial Guinea, countries grappling with conflict, inequality and political instability.

The American pope's comments aboard the plane are his strongest to date pushing back against criticism from the American president. 

Amid the backdrop of the war in Iran, Leo has repeatedly warned in recent days that violence is becoming normalized and that religious language is at risk of being misused to justify it.