Francis last Sunday (January 23) called on people of all religious to pray on Wednesday for an end to the crisis, saying the tensions were threatening the security of Europe and risking vast repercussions.
"I ask you to pray for peace in Ukraine and to do it often in the course of the day," Francis said at his weekly general audience, adding that he hoped "wounds, fears, and divisions" can be overcome.
As people prayed in Ukraine and elsewhere, Francis said he hoped that the "supplications that today rise up to heaven touch the minds and hearts of world leaders, so that dialogue may prevail and the common good be placed ahead of partisan interests".
The Vatican's foreign minister, Archbishop Paul Gallagher, was leading a prayer service in Rome on Wednesday evening organised by the Sant'Egidio community, a Rome-based international charitable that promotes peace.
Western leaders have stepped up military preparations and made plans to shield Europe from a potential energy supply shock if Russian invades Ukraine.
Top U.S. and Russian diplomats failed on Friday (January 21) to make a major breakthrough in talks to resolve the crisis, although they agreed to keep talking.