His visit falls in amid of ongoing upheaval in the country, where pro-Russian separatists in the east have been fighting government forces since April 2014. The conflict has killed nearly 10,000, and displaced millions.
The fighting in eastern Ukraine followed closely on the March 2014 annexation of Crimea, a Ukrainian territory, by Russia. Russia is also believed by Western governments to be assisting the rebels in Ukraine's Donetsk and Luhansk oblasts; a claim denied by Moscow.
In his speech, Cardinal Sandri said he would carry with him the various celebrations and meetings he had while in Ukraine, particularly his visit to the eastern, conflict-ridden region of the country "so tried by the battles which have forced many of your brothers and sisters to flee."
"I have seen the pain, but also many signs of hope, like many flames which slowly light a great fire," he said, and pointed to the example of displaced persons who, despite their own situation, have begun to work with the local Caritas to "alleviate the pain and deprivation" of others in the same situations.
He pointed to the example of priests, both Greek-Catholic and Latin rite, who during the years of communism were imprisoned or deported.
In addition to these, he also pointed to priests who "in recent episodes of war that have have bloodied your land have protected and saved as many as they could," despite being in danger themselves.
As youth, who get the majority of their information through various forms of social media, the cardinal asked that they think of the suffering children in other parts of the world have to endure, such as the students and volunteers of the Jeremiah Educational Center of Faisalabad, Pakistan, who are persecuted "for their faith in Jesus."
He also asked youth to consider stopping to pray the rosary, and in so doing, send "the embrace of Jesus" to the British infant Charlie Gard and his family, who are in the midst of a legal battle over treatment for the critically ill child.
"The exercise of intelligence to understand the present, prayer, charity and solidarity are ways in which you can also start to walk, like Mary," he said.
Cardinal Sandri then told the youth to read and meditate on Pope Francis' message for the upcoming World Youth Day in Panama in 2019.
In his message, the Pope asks that youth "continue your steps not only remembering the past, but also having the courage in the present and hope for the future, to recognize your origins, to always return to the essential and to throw yourself with creative fidelity into the building of new horizons," Cardinal Sandri said.
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"You are the salt and light of this world; don't resign to thinking that things cannot change," he said, telling them to "change society, where often the strongest and corrupt dominate, through a pure heart, faithful to God, faithful to the most authentic humanity."
The cardinal also told attendees to "allow the oil of God's consolation to soothe the inner wounds of so many," particularly young women manipulated into being surrogate mothers – which he called "a terrible practice" increasingly banned by countries – and those who have had abortions.
"Let us pray that they feel the desire for the caress of God's mercy and commit ourselves for a new surge of the defense of the dignity of women and children from every form of trafficking and exploitation," he said.
Cardinal Sandri closed his speech asking the youth to also help their priests prepare for the upcoming synod of bishops in 2018, dedicated to "Young People, Faith and the Discernment of Vocation."
The cardinal noted how in the Pope's letter to youth, published alongside the initial outline of the synod discussion, Francis wrote: "Can things change? YES."
"This cries from your young heart which does not bear injustice and cannot bend to the culture of waste, and neither can it believe in the globalization of indifference!" he said, quoting the Pope.