Pope Francis will create five new cardinals from outside Italy and the Vatican in a surprise move that blindsided even close confidants.

The announcement, made at the end of his weekly Sunday address from St Peter's Square, is seen as part of Francis' attempt to make the Catholic Church less Italian and Vatican-centric.

The power to name cardinals, elite churchman who elect the next pope, is one of the reigning pontiff's most significant powers.

Pope Francis' choice to promote five, including three from countries with tiny Catholic populations, fits with his desire to support areas where believers are in the minority.

The new 'princes of the Church' are Archbishop Jean Zerbo, 73, of Bamako, Mali, Archbishop Juan José Omella, 71, of Barcelona, Spain, Bishop Anders Arborelius, 67, of Stockholm, Bishop Louis-Marie Ling Mangkhanekhoun, 73, of Pakse, Laos, and Bishop Gregorio Rosa Chávez, 74, of San Salvador.

Since all are aged under 80, they can enter the secret conclave to choose a new pope after Francis dies or resigns. As such they are known as 'cardinal electors'.

The naming of a cardinal for Sweden was significant because Sweden is where the Lutheran World Federation was founded in 1947 and because this year marks the 500th anniversary of Martin Luther's Reformation.

Francis, who visited Sweden last year, is keen to further Catholic dialogue with Protestant churches.

Sweden is also one of the world's most secular countries and the naming of a cardinal there will boost the morale of the tiny Catholic population.

Including the current batch, Francis has named nearly 50 cardinal-electors, or about 40 percent of the total of 120 allowed by Church law.

Additional reporting from Reuters.