Donald Trump’s views on immigration has been denounced by Pope Francis, saying they were “not Christian.” Trump has responded to the criticism by calling the Pope “disgraceful” for questioning his faith.

The pontiff was on a brief tour to Mexico and while returning back to Rome, he told reporters that, “A person who thinks only about building walls, wherever they may be, and not building bridges, is not Christian.”

Trump’s response to it came shortly after the Pope made his comment.

“For a religious leader to question a person’s faith is disgraceful,” the Guardian quoted him as telling a packed room at a golf course resort. “No leader, especially a religious leader, has the right to question another man’s religion or faith.” He then hit back at the Mexican government for “using the pope as a pawn.”

“They should be ashamed of themselves, especially when so many lives are involved and illegal immigration is rampant and bad for the United States,” he added.

During an in-flight conference, Pope Francis said that he had no intention of influencing any American with his comments. “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,” he said. “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 in this I give the benefit of the doubt.”

In a press release, the Republican candidate said that the Pope would regret not supporting his candidacy. If and when the Vatican is attacked by ISIS, which as everyone knows is ISIS’ “ultimate trophy,” Trump said, “the pope can have only wished and prayed that Donald Trump would have been president because this would not have happened. ISIS would have been eradicated unlike what is happening now with our all talk, no action politicians.”

Trump, however, said that he did not take the Pope’s comment personally. He has been promising to build a wall along the US’s border with Mexico, throughout his campaign, and proposed the government to effectuate a temporary ban on Muslims across the world, reports Sky News.

The Pontiff, on the other hand, made the comments while speaking to the reporters on Thursday, and during the conversations, he also discussed the potential softening of the Church’s ban on contraception because of the Zika virus, said Sky News.