A South African archbishop who has just been promoted to a cardinal by Pope Francis has expressed bewilderment and confusion about his upcoming ascension to one of the top ranks of the Catholic Church.

"I have been taken by surprise and to be honest - I feel quite confused and bewildered at the moment,” Archbishop Stephen Brislin from Cape Town said.

He added that he hoped he could follow the good example of previous cardinals.

His comments come after the pope appointed 21 new cardinals, three of whom are African.

The others are Archbishop Stephen Ameyu Martin Mulla of Juba, South Sudan and Archbishop Protase Rugambwa of Tabora Archdiocese in Tanzania.

There've been calls for greater African representation in the Catholic church.

It was highlighted in January that none of the continent's cardinals hold major offices within the institution.

The ceremony to install the new cardinals is set to take place at the end of September.