Donald Trump lashed out Thursday after Pope Francis questioned his Christianity, saying the pontiff will “wish and pray” he the real estate mogul were President “if and when the Vatican is attacked.”

“So if and when the Vatican is attacked by ISIS, which as everyone knows is ISIS’ ultimate trophy, I can promise you that the pope would have only wished and prayed that Donald Trump would have been president,” Trump said during an appearance in South Carolina.

The real estate mogul admits he “likes” the pope, but said his comments were “disgraceful.”

“For a religious leader to question a person’s faith is disgraceful,” Trump said in a statement released today. “I am proud to be a Christian and as President I will not allow Christianity to be consistently attacked and weakened, unlike what is happening now, with our current President. No leader, especially a religious leader, should have the right to question another man’s religion or faith.”

Earlier, Pope Francis alluded to Trump in an interview, saying a man who thinks about building walls instead of bridges is “not Christian.”

“A person who thinks only about building walls, wherever they may be, and not of building bridges, is not Christian,” the pontiff said Thursday aboard the papal flight today. “This is not the gospel. As far as what you said about whether I would advise to vote or not to vote, I am not going to get involved in that. I say only that this man is not Christian if he has said things like that. We must see if he said things in that way and I will give him the benefit of the doubt.”

The Republican frontrunner also argued today in South Carolina that the Mexican government is “using the Pope as a pawn” and wrongfully feeding the pope information.

“That’s the Mexican government,” he said. “They should be ashamed of themselves for doing so, especially when so many lives are involved and when illegal immigration is so rampant and so dangerous and so bad for the United States.”

Trump’s social media chief Dan Scavino also tweeted a map of Vatican City, pointing out the walls that surround it.