Pope Francis has again diversified the body of select Catholic prelates, creating 17 new cardinals from 11 different countries including seven that have not had cardinals before.

The countries that have previously never had a cardinal, but now do, are the Central African Republic, Bangladesh, Mauritius Island, Papua New Guinea, Malaysia, Lesotho and Albania.

The Vatican's apostolic nuncio, or ambassador, in Syria - Italian Archbishop Mario Zenari - was also named as a cardinal by Francis, who described the country as "beloved and tormented."

Elsewhere, the pope included three US bishops for the role: Chicago Archbishop Blase Cupich, Indianapolis Archbishop Joseph Tobin, and the newly appointed Vatican official Bishop Kevin Farrell.

Francis made the announcement of the new cardinals during his weekly Sunday address following the Angelus prayer at noon in St Peter's Square.

Cardinals, sometimes known as the "princes of the church" usually serve either as archbishops in the world's largest dioceses or in the Vatican's central bureaucracy.

One of their main roles is to vote to elect a new pope after an existing one has died or resigned.

Of the 17 cardinals Francis named yesterday, 13 are under the age of 80, at which point cardinals can no longer vote in conclave.

Francis has sought to diversify representation in the group, choosing cardinals for parts of the world that have been underrepresented or not represented at all.

Of the pope's 17 choices announced yesterday, four come from Europe, three from the US, three from Latin America, two from Africa, two from wider Asia, two from island nations, and one currently representing the church in the Middle East.

The National Catholic Reporter said that the appointment of three new US cardinals comes at a significant time for the American church, as bishops will be meeting in Baltimore for their annual assembly 14-17 November, when they will elect new officers.

Announcing the names of the new cardinals yesterday, the pope said the group "expresses the universality of the church, which proclaims and witnesses to the Gospel of the Good News of the Mercy of God in every corner of the earth."

On the papal flight back to Rome from Azerbaijan on 2 October, the pope discussed his thinking behind the new appointments, saying his main concern was to have a balance of representation from around the world.

He said he wanted a balance so "you see in the College of Cardinals the universality of the church". He added: "The list is long but there are only 13 spots...You have to think about having a balance."

With the 17 new cardinal-elects, the number of voting cardinals becomes 121, and the number of non-voting cardinals to 107, for a total of 228.