VATICAN CITY (CNA/EWTN News) - Christians must work to abolish the death penalty and improve prison conditions, Pope Francis said on Sunday.

After praying the Angelus on Sunday in St. Peter's Square, Pope Francis called on all Christians and people of good will to work "not only for the abolition of the death penalty" but also to improve the conditions in prison. These efforts would respect the human dignity of prisoners, he said.

He appealed to the consciences of government leaders to join "the international consensus for the abolition of the death penalty." He asked Catholic leaders not to hold executions during the Year of Mercy. This would be as a "courageous and exemplary act," he said Feb. 21.

Rome will host an international convention for those working to abolish the death penalty on Feb. 22. The event is being promoted by the Sant'Egidio Community.

Pope Francis said he hoped that the gathering can strengthen efforts to abolish capital punishment.

"The commandment 'Thou shall not kill' has absolute value and concerns both the innocent and the guilty," he said. Even criminals "maintain the inviolable right to life, the gift of God."

He said the penal system must always be open to the hope of reintegrating criminals into society.

The Pope condemned the death penalty on Sept. 24, 2015 during his visit to the United States.

"The Golden Rule also reminds us of our responsibility to protect and defend human life at every stage of its development," he told a joint meeting of Congress.

Before the Angelus on Sunday, Pope Francis discussed the Gospel reading and the Transfiguration of Jesus. He connected this to his recent trip to Mexico.

The Pope said his apostolic visit to Mexico was "an experience of transfiguration." He added: "the Lord has shown us the light of his glory through the body of the Church, the body of his holy people who live in that land."

The Pope spoke with many people during the Feb. 12-18 visit, including families, workers and prisoners.

He said these people gave "a testimony of a clear and strong faith, the testimony of a lived faith, of a faith that transfigures life."