Holy Father says Trump's views not Christian

Pope Francis forcefully injected himself into the U.S. presidential campaign on Thursday, assailing Republican candidate Donald Trump's views on U.S. immigration as "not Christian" in a sign of growing international concern at the billionaire businessman's election prospects.

Trump struck back. No stranger to controversy, the longtime party front-runner in national opinion polls dismissed the leader of the world's Roman Catholics as "disgraceful" for questioning his faith. He said he was a proud Christian.

Francis told reporters during a free-wheeling conversation on his flight home from a visit to Mexico: "A person who thinks only about building walls, wherever they may be, and not building bridges, is not Christian."

Trump has accused Mexico of sending rapists and drug-runners across the United States' southern border and has vowed if elected president to build a wall to keep out immigrants who enter illegally.

More than half a million Britons signed a petition to bar him from entering Britain, where he has business interests, in response to his call to temporarily ban Muslims from entering the United States. British lawmakers decided against a ban as a violation of free speech.

Asked if American Catholics should vote for someone with Trump's views, Francis said: "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 in this I give the benefit of the doubt."

It remained to be seen if the pope's comments would strengthen Trump in the run-up to the Nov. 8 election to succeed Democratic President Barack Obama. Trump's swipes at rival candidates and heated exchanges with others have bolstered his standing in nominating contests and opinion polls.

One of Trump's Republican rivals, former Florida Governor Jeb Bush, speaking in Columbia, South Carolina, said he would not question anyone's relationship with God. But Bush, a Catholic, said: "It only enables bad behavior when someone from outside our country talks about Donald Trump."