Pope Francis has designated Wednesday a day of prayer for peace in Ukraine amid fears of an invasion by Russia.

In his Sunday Angelus, the Pope expressed fears that a conflict between Russia and Ukraine could have wider security implications for the whole of Europe. 

"I make a heartfelt appeal to all people of good will to raise prayers to Almighty God that all political actions and initiatives may be at the service of human brotherhood rather than partisan interests," he said. 

Catholic bishops in Poland and Ukraine have also issued a joint appeal for dialogue aimed at averting a war from which there might be "no turning back". 

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Their statement echoes the Pope's fears in warning that any conflict will lead to "senseless slaughter" and be a "great threat" not only to the countries of Central and Eastern Europe, but also "the entire European continent". 

"It is with concern that we learn the news that the recent rounds of talks between Russia and the West have not led to an agreement," they said. 

Signatories of the statement include the Primate of the Ukrainian Greek Catholic Church and the President of the Polish Bishops' Conference. 

The statement continues, "We want to underline clearly that every war is a disgrace and can never be an appropriate way to solve international problems. It never has been and it never will be because it creates new, more serious conflicts."

It goes on to call on leaders to take steps to "refrain from war".

"We call on leaders to withdraw ultimatums immediately and not to take advantage of other countries as bargaining chips. Any divergence of interests should be resolved not through the use of arms but through agreements," the bishops said.