VATICAN CITY -- All wars are "utter disasters" for everyone, especially families, children, the elderly, refugees, communities and creation, Pope Francis said.

"As followers of Christ, we must not grow resigned to war but work together for peace," he told a delegation of Orthodox leaders during a meeting at the Vatican June 30.

"At the same time, (peace) remains a gift that requires acceptance by men and women, particularly believers, who are called to share in God's work of peacemaking," he said in a written address handed to the delegation.

The delegation representing the Orthodox Ecumenical Patriarchate of Constantinople was in Rome for the June 29 feast of Sts. Peter and Paul. Metropolitan Job of Pisidia, the Orthodox co-president of the joint international commission for Catholic-Orthodox theological dialogue, led the delegation, which met with officials at the Dicastery for Promoting Christian Unity June 29 and the pope June 30.

In the text he had prepared for the meeting, Pope Francis highlighted the Catholic and Orthodox shared concern for peace, "especially in war-torn Ukraine."

"It is a war that closely affects us; it demonstrates how all wars are in fact disasters, utter disasters: for peoples and families, for children and the elderly, for people forced to leave their country, for cities and villages, and for creation, as we have recently seen following the destruction of the Nova Kakhovka dam," the pope wrote.

"The tragic reality of this apparently interminable war requires a common creative effort on the part of all to envision and create paths of peace, in view of a just and stable peace," he added.

Peace must rise from the human heart, he wrote. "What stands in the way of peace is ultimately the bitter root that we carry within us: greed, the selfish desire to pursue our own interests at the personal, community, national and even religious levels."

"The remedy is the conversion of hearts, renewing them with the love of the Father," he wrote. It is "a gracious and universal love that is not confined to our own group."

The lives of believers in Christ must proclaim "the newness of this love," he wrote, otherwise "how can we bear witness to Jesus before the world?"

Attitudes that are "self-centered and self-seeking" must be replaced by God's "style," which is one of "service and self-renunciation. We can be sure that, by incarnating that style, Christians will grow in reciprocal communion and will assist our world, marked as it is by division and discord."

Pope Francis also wrote about the gift of full Christian unity that is to be sought in the Holy Spirit. "For communion between believers is not a matter of concessions and compromises, but of fraternal charity between brothers who acknowledge that they are beloved children of the Father and, filled with the Spirit of Christ, are capable of setting their diversity within a larger context."

The latest plenary session of the joint commission for theological dialogue, held in Alexandria, Egypt, engaged in "a joint reading of the way in which the relationship between synodality and primacy developed in East and West during the second millennium," the pope wrote.

Today, he wrote, "we are called to seek together a modality of exercising the primacy that, within the context of synodality, is at the service of the church's communion on the universal level."

The pope underlined that the prerogatives that the pope, as bishop of Rome, enjoys in his own diocese and with the global Catholic community should not be extended to the Orthodox communities.

"When, with the help of God, we shall be fully united in faith and love, the form in which the bishop of Rome will exercise his service of communion in the church at the universal level will have to be the result of an inseparable relationship between primacy and synodality," he wrote.