Pope Francis said on Sunday he would appoint 21 new cardinals from across the world, including Hong Kong Bishop Stephen Chow, at the end of September.

"Their provenance expresses the universality of the Church that continues to proclaim God's merciful love to all people on earth," said the pope, following his weekly Sunday Angelus prayer from the window of the Apostolic Palace on Saint Peter's Square.

Besides Chow, the new cardinals include the bishop of Penang and the Vatican’s top official in the Middle East, Monsignor Pierbattista Pizzaballa, the Latin Patriarch of Jerusalem.

Among the others tapped are several prelates holding or about to assume major Vatican posts, like Argentine Archbishop Victor Manuel Fernandez, whom the pope just named to lead the office for ensuring doctrinal orthodoxy.

The ceremony to formally install the churchmen as cardinals will be held on September 30.

The pope's choices are closely watched as cardinals under the age of 80 will participate in the vote to nominate the successor to Francis.

Chow, 63, was appointed bishop of Hong Kong in May 2021. He will be the fourth cardinal from the Hong Kong diocese, after the late John Baptist Wu, Joseph Zen and John Tong. (Agencies)