VATICAN CITY -- Cardinal Francois Xavier Nguyen Van Thuan, who suffered 13 years of imprisonment in communist Vietnam, died Sept. 16 in Rome after an extended battle with cancer. He was 74.

In a telegram, Pope John Paul II said Cardinal Thuan leaves the "indelible memory of a life spent in coherent and heroic adhesion to his vocation as priest" and as a "pastor full of zeal for the Gospel (who was) always faithful to the church even in the difficult time of persecution."

He said the late cardinal accepted his "long and painful illness" with "serenity and a spirit of intense participation in the cross of Christ."

The pontiff was to preside at a funeral Mass Sept. 20 in St. Peter's Basilica for the cardinal, who headed the Pontifical Council for Justice and Peace since 1998 and was made a cardinal last year.

Bishop Giampaolo Crepaldi, secretary of the justice and peace council, said Cardinal Thuan was "an extraordinary Christian who lived the Gospel to its roots."

"He was a man of hope, peace, forgiveness and reconciliation," Bishop Crepaldi told Catholic News Service. "For me his death is a great sorrow. But his voice will continue to be heard."

Cardinal Thuan had been hospitalized for several months in Rome's Casa di Cura Pius XI clinic. He had undergone two cancer operations, including one in Boston last year.

The cardinal's prison experiences shaped his spiritual outlook and were a constant theme in his numerous public speaking engagements around the world. Even after fleeing Vietnam more than a decade ago, he continued to wear a pectoral cross and chain he fashioned in prison out of wood and electrical wire and which he hid from guards in a bar of soap.

"I wear this cross and this chain every day," he explained at a conference in Los Angeles in 2000, "not because they are reminders of prison, but because they indicate my profound conviction, a constant reference point for me: Only Christian love can change hearts; neither weapons, nor threats nor the media can do so."

He repeatedly said he bore his guards no ill will and even tried to become friends with them, answering their questions about the Catholic Church in an attempt at evangelization.

In 2000, the pope, calling Cardinal Thuan's suffering a "witness of the cross," asked him to lead the Vatican's Lenten retreat. The cardinal's talks focused on his prison experiences to illustrate the role suffering can play in realizing the truth of God's mercy and presence in daily life.

He also published several books about his detention, including Five Loaves and Two Fish, The Road of Hope: A Gospel from Prison, and Prayers of Hope: Words of Courage.

Vietnam's communist regime jailed the cardinal in 1975 when he was the newly named coadjutor bishop of Saigon, later renamed Ho Chi Minh City. He was never tried or sentenced and spent nine of his 13 years of detention in solitary confinement.

His uncle was South Vietnamese President Ngo Dinh Diem, a Catholic who was assassinated in 1963.

After Cardinal Thuan's release in 1988, the communist authorities refused to let him resume his post or to be reassigned, at the Vatican's request, to the Archdiocese of Hanoi. Vietnam, which does not have diplomatic relations with the Vatican, requires government approval of all bishops' nominations.