Presenting a publication that reaffirmed the Vatican's opposition to sex changes, gender theory and surrogate parenthood, Cardinal Victor Manuel Fernandez called laws punishing homosexuality "a big problem".

"Of course we are not in favour of criminalisation," he said on Monday.

The Vatican's doctrinal office (DDF) released the "Dignitas infinita" (Infinite dignity) declaration following fierce conservative pushback, especially in Africa, against its document on LGBTQI issues.

There is no suggestion that the new text, which describes what the church perceives as threats to human dignity, was prepared in direct response to the rows over same-sex blessings, as it has been five years in the making.

But it has undergone extensive revisions during that time.

Pope Francis approved it after requesting that it also mention "poverty, the situation of migrants, violence against women, human trafficking, war, and other themes", Fernandez said in a statement.

The declaration said surrogate parenting violated the dignity of both the surrogate mother and the child, and recalled that Francis in January called it "despicable" and urged a global ban.

Fernandez, a liberal theologian whom Pope Francis appointed as head of the Vatican's Dicastery for the Doctrine of the Faith less than a year ago, told reporters it was "painful" to see some Catholics support anti-homosexuality laws.

In February 2023, returning from a trip to Africa where same-sex relationships are often taboo, Francis said laws criminalising LGBTQI people were a sin and an injustice, because God loves and accompanies people with same-sex attraction.

"The criminalisation of homosexuality is a problem that cannot be ignored," the Pope said, citing unnamed statistics according to which 50 countries criminalise LGBTQI people "in one way or another" and about 10 others have laws including the death penalty.

Under Francis, the Catholic Church has become more welcoming towards LGBTQI people.

In December, Cardinal Fernandez's office issued a landmark document allowing the blessing of same-sex couples, triggering substantial conservative backlash.

Nevertheless, the church officially teaches that homosexual acts "are intrinsically disordered".

Answering a question on whether such language might be amended, Cardinal Fernandez said "it is true that it a very strong expression and that it needs a lot of explanation, perhaps we could find a clearer one".

He said that the point of Catholic teaching was that homosexual acts cannot match "the immense beauty" of heterosexual unions, and the church "could find more apt words to express" this.

Australian Associated Press