The Catholic Pontiff, Pope Francis, has strongly criticized President-elect Donald Trump’s plans for large-scale deportations of undocumented migrants, calling it “a calamity.”

Trump has pledged to take a hardline stance against an estimated 11 million undocumented migrants in the United States.

“If it is true, it will be a calamity because it makes the poor wretches who have nothing pay,” Francis said in an interview with Italian television channel Nove.

The Pope has previously criticized Trump’s anti-migrant policies, saying, “Anyone, whoever he is, who only wants to build walls and not bridges is not a Christian.”

Trump’s plans include carrying out “the largest deportation operation in American history,” which is expected to face legal challenges and potential refusals by some countries to accept deportees.

The operation may begin with migrants who have committed crimes, but all undocumented migrants, including those with no criminal history, may be at risk of arrest and deportation.

Raids at construction sites, where undocumented migrants are often employed, are also expected to resume.

However, the operation could pose difficulties for officials due to limited custody space to hold detainees.

The Laken Riley Act, which requires the federal government to detain migrants living in the US illegally who are suspected of criminal activity, is expected to be passed by Congress next week. Trump has also vowed to end birthright citizenship, calling it “ridiculous,” despite it being guaranteed by the US constitution.

Analysts expect Trump to issue executive orders on other aspects of immigration policy and potentially declare a national emergency to unlock Pentagon resources.

The American Civil Liberties Union (ACLU) has expressed concerns about the legality and constitutionality of Trump’s deportation plans.