Nominees from far-flung places include 13 cardinals under 80 years old who could potentially succeed present pontiff.

Pope Francis has promoted 17 Roman Catholic prelates from around the world to the high rank of cardinal, including 13 who are under 80 years of age and thus eligible to succeed him one day.

Francis, making the surprise announcement during his weekly address, said on Sunday that the ceremony to elevate the prelates, known as a consistory, would be held on November 19.

"Their provenance from 11 nations expresses the universality of the church that announces and is witness to the good news of the mercy of God in every corner of the world," Francis said.

The new cardinal-electors, those under 80, come from Italy, the Central African Republic, Spain, the US, Brazil, Bangladesh, Venezuela, Belgium, Mauritius, Mexico and Papua New Guinea.

Only one of the 13 cardinal-electors will take on a Vatican job. The others would remain in their posts around the world.

Significantly, Francis said the current Vatican ambassador in Syria, Italian Archbishop Mario Zenari, would be elevated but remain in his post to show the Church’s concern for "beloved and martyred Syria" - an allusion to the devastating civil war there.

It was believed to be the first time in recent history a Vatican ambassador, known as a nuncio, would have the rank of cardinal.

Focus on mercy

Three of cardinal-electors are American moderates, including Chicago Archbishop Blase Cupich and Indianapolis Archbishop Joseph Tobin, a clear signal to the conservative US church hierarchy that he values pastors focused more on mercy than morals.

The four new cardinals over 80, who get the position as a symbolic honour to thank them for long service to the Church, include Father Ernest Simoni, 88, an Albanian priest who spent many years in jail and forced labour during the communist dictatorship of Enver Hoxha, who died in 1985.

In addition to Simoni, the other three cardinals over 80 come from Malaysia, Italy and Lesotho.

Cardinals, who wear red hats and are known as "princes of the Church," are the most senior members of the Roman Catholic hierarchy after the pope and serve as his principal advisers around the world and in the Vatican.

Naming new cardinals is one of the most significant powers of the papacy, allowing a pontiff to put his stamp on the future of the 1.2-billion-member global Church.

Cardinals under 80, known as cardinal-electors, can enter a secret conclave to choose a new pope from their own ranks after Francis dies or resigns.

Francis, the former cardinal-archbishop of Buenos Aires, was elected in a conclave on March 13, 2013.

With the current batch, Francis has named 44 cardinal-electors, slightly more than two-thirds of the total of 120 allowed by Church law.

It will be his third consistory since his election in 2013 as the first non-European pontiff in 1,300 years and he has used each occasion to show support for the Church in far-flung places or where Catholics are suffering.

The Central African Republic, Bangladesh, Papua New Guinea, Malaysia and Lesotho will have a cardinal for the first time, underscoring Francis’ conviction that the Church is a global institution that should become increasingly less Euro-centric.

Three of cardinal-electors are American moderates