Pope Francis has called on the world to join him on a day of prayer Wednesday, concerned over the increase of tensions which threaten to inflict a new blow to peace in Ukraine and “call into question the security of the European continent.”

“Whoever pursues his own goals to the detriment of others, despises his own vocation as a man, because we have all been created brothers,” he said on Sunday at the end of the Angelus.

Though Francis didn’t go into details, he was referring to Russia’s apparent decision to escalate its conflict with Ukraine. It began back in early 2014, when Vladimir Putin invaded and subsequently annexed the Crimean Peninsula, in the wake of the 2014 Ukrainian revolution.

The papal representative to Ukraine, Archbishop Visvaldas Kulbokas, said that the local people consider Francis to be among the most respected religious figures, so Sunday’s appeal “was immediately received as very important news, which lifts the heart, expresses closeness and solidarity.”

Knowing that “you are not alone and forgotten” during these difficult times in Ukraine “is already a great help.”

Major Archbishop Svatoslav Shevchuk, head of the Ukrainian Greek Catholic Church, released a video message personally inviting people to respond to the pope’s appeal for prayer.

“Why do we so much need to pray for peace in Ukraine today?” he asks. “When new dangers arise and the enemy is on our doorstep, our military checks their combat efficiency, statesmen work to streamline social mechanisms, diplomats work to ensure that the world supports our people and our state. And what are Christians doing? Christians right now are praying, fasting and repenting of their sins.”

According to Shevchuk, who spent his formative years as a seminarian in Buenos Aires, Pope Francis’s home archdiocese, “prayer for peace is more powerful than any weapon.”

“I invite all the children of our Church to join the spiritual vigil of prayer,” Shevchuk said. “Wherever you are – at home or on transportation, on your way to work or at your workplace, at school or at university – I ask you to pray for peace in Ukraine.”

“May prayer, together with fasting and penance, be stronger than any modern weapon,” he appealed. “May God preserve peace in Ukraine and in the whole world! May on this day our personal and common prayer be heard throughout the world for peace in Ukraine!”

Shevchuk is also among the co-signatories of a joint appeal issued by Latin Rite Catholic and Greek Catholic Church leaders in Poland and Ukraine, who issued a joint appeal for dialogue and understanding, and also requesting international support for the Ukrainian people.

“In the end, war is always a defeat for mankind,” write the prelates, including Archbishop Stanisław Gądecki, head of the Polish bishops’ conference. “It is an expression of barbarity and an ineffective tool for resolving disputes … [as well as] a crime against God and man himself.”

“We appeal to rulers to refrain from hostilities,” they continue. “The present situation requires Christians of eastern and western traditions to be fully responsible for the present and future of our continent.”

Gądecki announced that the Polish Church would be responding to Pope Francis’s appeal by declaring Wednesday a national day of prayer and fasting for peace in their neighboring country.

During the Christmas season, “some 100,000 Russian troops have been positioned on three sides of Ukraine.” As the Greek Catholic Ukrainian bishops in the United States wrote in their statement asking for prayers, this European country that gained its independence after the fall of the Soviet Union, is “a nascent democracy, a country on a pilgrimage to freedom and dignity from the fear of a totalitarian past in which 15 million people were killed on Ukrainian territory.”

Geographically, it’s the second largest country in Europe, after Russia, and with its over 40 million inhabitants, the eight most populous in the continent.

On Monday, United States’ Defense Secretary Lloyd Austin placed 8,500 U.S. troops on “heightened preparedness to deploy” at President Joe Biden’s direction. The U.S. has also sent multiple consignments of weapons to Ukraine in recent days as part of $200 million of defensive aid. The European Union plans to help Ukraine with a 1.2 billion euro – $1.36 billion – financial aid package.

As the U.S., the EU, and NATO ready to help Ukraine fight Russia, bishops around the world are instead urging the faithful to join in prayer for peace.

“Today, the world watches and wonders: Are religious liberty, a free press, a robust public debate, and accountable government in a sovereign state to be punished through the escalation of an invasion that began in 2014?” wrote the five Greek Catholic Ukrainian bishops of the United States. “Is the Ukrainian people’s exercise of their God-given dignity a threat to a modern Herod’s thirst for power and hegemony?”

They denounce that “nostalgia for an empire lost” has led to “senseless slaughter and immense suffering throughout Ukraine.”

“God-given human dignity and freedom threaten rulers who seek to dominate others, build empires, enslave, and colonize,” they wrote. “Those with the audacity to resist, who dare to move from the fear of totalitarianism to freedom and dignity are mercilessly punished.”

They close their statement urging the faithful to “pray, be informed and help the suffering,” including a link for donations to “help the victims of the senseless invasion.”

The World Council of Churches (WCC) acting general secretary Rev. Ioan Sauca, on behalf of WCC member churches throughout the world, joined the voices of those who are “urgently” appealing for peace in Ukraine.

“As we follow the news of the mad progression towards war, we plead for a different logic than one based on geopolitical competition – a logic that considers the death and suffering that any armed conflict would inevitably visit on the children, women and men of Ukraine,” said Sauca. “We pray for a change of hearts and minds, for de-escalation, and for dialogue instead of threats.”

God’s people – and members of the ecumenical fellowship – find themselves on both sides of the current confrontation, added Sauca.

“But our God is a God of peace, not of war and bloodshed,” he said. “Though the things that make for peace may be hidden from the eyes of those driving the march to war, we pray that they may yet be opened, and that peace may yet prevail.”