The Vatican has expressed "regret" over the charges of historical sex abuse faced by Cardinal George Pell, Australia's most senior Catholic.

In the Catholic Church's long-running sex abuse scandal, Pell is the highest-ranking Vatican official ever to be charged.

Vatican spokesman Greg Burke said Pope Francis has appreciated Pell's "honesty and commitment" during his three years working to reform the Vatican's finances.

In a statement read to reporters, Burke recalled that Pell has "openly and repeatedly condemned as immoral and intolerable" acts of sexual abuse against minors.

He noted that Pell has cooperated with Australia's Royal Commission investigation into sex abuse and that as a bishop in Australia he worked to protect children and compensate victims.

The statement said the Holy See had learned "with regret" of the charges and that Francis had granted Pell a leave of absence to defend himself. Police in the Australian state of Victoria said there were multiple charges against Pell and that the case involved "multiple complainants".

Pell appeared before reporters on Thursday, 29 June, to deny the accusations, denounce what he called a "relentless character assassination" in the media, and announce he would return to Australia to face the charges.

Pell will appear at Melbourne Magistrates Court on the 18 July this year for a filing hearing. The Cardinal said he is taking a leave of absence as the Vatican's finance czar.

Cardinal George Pell at the Vatican
Cardinal George Pell has been charged with historical sex offences VINCENZO PINTO/AFP/Getty Images