Pope Francis lamented the world's indifference to the flood of refugees from war-torn countries sweeping Europe, comparing today's leaders to the authorities who did not want anything to do with Jesus Christ, leading to His crucifixion.

The pope made the comparison in his homily at an outdoor Mass in St. Peter's Square to mark Palm Sunday, the Associated Press reported.

Before the mass, Pope Francis led a procession to mark the start of Holy Week. Thousands of Catholics waving olive branches and braided palm fronds received his blessing.

Departing from his prepared sermon, the pope expressed strong disapproval of Europe's handling of the thousands of refugees from Syria, Iraq, Africa and elsewhere who are fleeing from war, persecution or poverty.

He compared the suffering refugees to Jesus Christ who was "denied every justice" and "suffered on his own skin indifference, because no one wanted to take on the responsibility for his destiny."

"And I am thinking of so many people, so many on the margins, so many refugees" for whom "many don't want to assume responsibility for their destiny," Pope Francis said, referring to European leaders who wanted to get rid of the unwelcomed migrants in their countries. EU and Turkish officials earlier made a deal to send back to Turkey migrants now arriving on Greek islands.

In his homily, Pope Francis urged Christians to contemplate Jesus' Passion and Death throughout the Holy Week and bear in mind that salvation is attained through humility and service, the Catholic News Agency said.

"Today's liturgy teaches us that the Lord has not saved us by his triumphal entry or by means of powerful miracles," the Pope said.

Instead, in the day's second reading from St. Paul to the Philippians, the apostle "epitomises in two verbs the path of redemption: Jesus 'emptied' and 'humbled' himself."

These two verbs, the pontiff said, "show the boundlessness of God's love for us. Jesus emptied himself: he did not cling to the glory that was his as the Son of God, but became the Son of man in order to be in solidarity with us sinners in all things; yet he was without sin."

Pope Francis reminded the faithful that Jesus chose to become a servant of the people rather than a king.

Just as Jesus entered Jerusalem on the back of a donkey, the Son of God also wants to enter people's lives in the same way, the pope said. "He comes to us in humility; he comes in the name of the Lord."