VATICAN CITY, MARCH 20, 2005 (Zenit.org).- John Paul II was unable to preside over Palm Sunday Mass for the first time in his 26-year papacy, but he did make a brief appearance at his apartment window.

The tens of thousands of pilgrims gathered in St. Peter's Square cheered when the Pope appeared for a few minutes at the end of Mass today. The Holy Father then blessed the crowd with an olive branch.

The Pope's vicar for Rome, Cardinal Camillo Ruini, presided at the Palm Sunday Mass.

John Paul II rapped his glass lectern vigorously, when aides stationed behind him signaled that he had spent enough time exposed to the elements.

Following the Mass, and before the recitation of the Angelus at midday, Archbishop Leonardo Sandri, substitute of the Vatican Secretariat of State, read the address that the Pope had prepared for the occasion, in which he recalled the 20th anniversary of the first World Youth Day.

The Pope's message encouraged young people to attend the next World Youth Day in Cologne, Germany, in August.

"Today you adore the cross of Christ, which you carry throughout the world, because you have believed in the love of God, fully revealed in Christ crucified," the Pope said in his message.

"Continue tirelessly on the path undertaken to be everywhere witnesses of the glorious cross of Christ. Be not afraid! May the joy of the Lord, crucified and risen, be your strength, and may Mary Most Holy always be by your side," he said.

When Archbishop Sandri began to read the message, he mentioned that the Pope had followed the Eucharistic celebration from his apartment.

The window to the Pope's apartment remained open during the Mass, with a palm branch hanging from it.

John Paul II, who returned to the Vatican last Sunday from the hospital, is not planning to preside at any of the Holy Week events. He is convalescing from a throat operation he underwent Feb. 24. He is, however, scheduled to give his tradition blessing to the world on Easter Sunday.

During the Palm Sunday Mass, prayers were recited in Portuguese for the Holy Father, with the hope that "the consolation of the Holy Spirit would illuminate and support him so that his witness of fidelity to Christ may be for all young people worldwide an example and model of supreme love for the One who chose him, in continual fidelity in his service to the giving of his life."