While I do not have access to information about a Pope Leo XIV, I can share information about the Catholic Church's stance on the war in Ukraine.

The Holy See has expressed grave concern regarding the war in Ukraine and has consistently called for peace 1 2.

Here's a summary of the Church's position:

• Call for Peace and Dialogue: The Holy See has consistently urged all parties to pursue peaceful resolutions through dialogue and negotiation 3 4 5 6. Pope Francis has appealed to political leaders to end the war and seek solutions that are consensual, just, and stable 3.
• Condemnation of War: The Church views war as a tragedy and an error 7 8. Pope Francis has lamented the immense human suffering, death, and destruction caused by the conflict 9 10.
• Humanitarian Efforts: The Holy See is actively involved in humanitarian initiatives aimed at alleviating the suffering of the Ukrainian population 11 12. This includes providing aid through the Dicastery for the Service of Charity and supporting the work of Catholic organizations on the ground 6.
• Support for Refugees: The Church has called on European societies and governments to welcome refugees fleeing the war in Ukraine and to offer them international protection 13 9 10 8. The Holy See implores that the displaced continue to receive humanitarian support until they can make a safe, voluntary and dignified return to their homes 7.
• Protection of Children and Families: The Holy See emphasizes the importance of family reunification and the protection of children affected by the war 14 3. It insists that States must refrain from evacuating children without a compelling medical reason and the written consent of those responsible for their care 14 3.
• Respect for International Law: The Church calls on all parties to adhere to international law and to avoid actions that would cause further suffering and destabilize coexistence between nations 1 10 8 2.
• Rejection of Violence: The Church denounces the reliance on tactics that treat soldiers as expendable objects and condemns acts of war aimed indiscriminately at the destruction of cities and populations 14 3 6.
• Efforts Towards Peace: Pope Francis has entrusted Cardinal Matteo Zuppi with leading missions to identify humanitarian gestures that could guide towards peace 7 5. The Holy See supports all efforts to promote peace in and around Ukraine 1 2.
• Warning Against Nuclear Escalation: The Church has cautioned against dangerous escalations of the conflict, particularly the threat of nuclear war, and has stressed the urgency of transforming the hearts of those who hold the outcome of the war in their hands 15 16 17 18.