U.S. President Donald Trump on Thursday said Pope Leo was free ​to say what he wanted but that it ‌was important for him to understand that Iran could never have a nuclear weapon.

Trump has repeatedly criticized the religious leader, who ​has emerged as an outspoken critic of the ​U.S.-Israeli war on Iran in recent weeks.

Trump says ⁠he is responsible for Leo's appointment, and has ​accused him of being "weak" on foreign policy.

"The Pope has to ​understand - it's very simple - Iran cannot have a nuclear weapon. The world would be in great danger," he told reporters at the ​White House.

Trump's criticism has triggered widespread backlash from ​U.S. Christians across the political spectrum.

Leo, originally from Chicago, decried the "madness of ‌war" ⁠in a peace appeal on Saturday.

The U.S. and Israel attacked Iran on February 28. Iran responded with its own strikes on Israel and Gulf states with U.S. ​bases. U.S.-Israeli strikes ​on Iran ⁠and Israeli attacks in Lebanon have killed thousands and displaced millions.

Leo told Reuters on ​Monday he would keep criticizing the war, ​regardless ⁠of Trump's comments.

"The Pope can say what he wants, and I want him to say what he wants, but ⁠I can ​disagree. I think that Iran ​cannot have a nuclear weapon," Trump said.