"An ordinariate for the faithful of eastern rite is a geographical ecclesiastical structure for Eastern Catholic communities in areas where no eparchy of their own particular Church has been established. This structure was introduced by the apostolic letter Officium supremi Apostolatus of 15 July 1912."
( Annuario Pontificio 2012 (Libreria Editrice Vaticana 2008, p. 1811)
The Ordinariate in Argentina, is for all Eastern Catholics, such as Ruthenian, Armenian, Ukrainian and Maronite, for example who lack a diocesan jurisdiction of their own rite in the particular country and who are therefore entrusted to the care of the Latin Metropolitan Archbishop.
Ukrainian Greek Catholic Patriarch Sviatoslav Shevchuk, welcoming the election of Pope Francis said, "I would first like to say that the newly elected Pope Francis was mentored by one of our priests, Stepan Chmil, who is now buried in the basilica of St. Sophia in Rome. Today’s Pope, during his time as a student of the Salesian school, awoke many hours before his classmates to concelebrate at our Divine Liturgy with Fr. Stepan. He knows our Tradition very well, as well as our Liturgy."
In fact, prior to his election as Supreme Pontiff as well as after, Pope Francis has been seen wearing a chotki, a prayer rope, a special set of prayer beads, usually made of wood or wool tied in knots (and occasionally silk) for praying the Jesus Prayer, or Prayer of the Heart.
As one formed in the Ukrainian Tradition, it is very obvious that His Holiness wears it as one who is very familiar with it and who makes use of it on a regular basis.