Updated

Pope Francis took an unexpected shot Monday at Catholics who criticize his calls for welcoming refugees and migrants with open arms, saying in a new document that "welcoming a stranger" is "exactly what Jesus demands of us."

In a not-so-veiled critique of right-wing conservative Christians in America, the Holy See issued a warning about ideologies that lead to “harmful errors” as part of the third apostolic exhortation of his papacy.

Likening opposition to abortion to welcoming migrants, Francis said defending “saints next door” is “equally sacred” to defending pre-born children from abortions.

"Some Catholics consider the situation of migrants to be a secondary issue," the Holy See wrote in his work, “Rejoice and Be Glad.” But Francis said that, while such a position was fine for politicians, Christians must think differently.

"Not a Christian for whom the only proper attitude is to stand in the shoes of those brothers and sisters of ours who risk their lives to offer a future to their children," Francis wrote. “Can we not realize that this is exactly what Jesus demands of us, when he tells us that in welcoming a stranger we welcome him?”

Francis also pointed to an Old Testament scripture about welcoming foreigners, saying the plea is not “a notion invented by some pope, or a momentary fad.”

French Archbishop Christopher Dufour said the majority of Catholics are encouraged by the pope’s stance on migrants, though he conceded there was opposition.

“And there is a small number who say: ‘he is naïve, let him come and live among migrants.’ It is not so simple," Dufour said.

The Associated Press contributed to this report.