"I assure you of my prayers for all your good intentions; and you too, please, pray for me," he said, before concluding by imparting his apostolic blessing.
The Pontifical Swiss Guard holds the title for the world's smallest but oldest standing army.
Every year, the guards commemorate the anniversary of the Sack of Rome with a weekend of events, attended by representatives of the Swiss army, Swiss government, and Swiss bishops' conference, as well as family and friends, and former guards.
In past years the festivities also included a concert and an audience with Pope Francis.
Due to the coronavirus and the restrictions placed on traveling and gathering in Italy at that time, the anniversary was marked this year by Mass followed by the "laying of the wreath," in the Square of the Roman Protomartyrs in Vatican City.
At the swearing-in ceremony on Sunday each new recruit will approach the flag of the Swiss Guard when his name is called out. Firmly grasping the banner with his left hand, the new guard raises his right hand and opens three fingers as a sign of his faith in the Holy Trinity.
As he holds up his fingers, the guard proclaims this oath: "I, (name), swear diligently and faithfully to abide by all that has just been read out to me, so grant me God and so help me his saints."
In English, the full oath reads: "I swear I will faithfully, loyally and honorably serve the Supreme Pontiff Francis and his legitimate successors, and also dedicate myself to them with all my strength, sacrificing if necessary also my life to defend them. I assume this same commitment with regard to the Sacred College of Cardinals whenever the see is vacant. Furthermore, I promise to the Commanding Captain and my other superiors respect, fidelity and obedience. This I swear! May God and our Holy Patrons assist me!"