VATICAN CITY (Reuters) - Pope Francis, in his first comments on the tensions between the West and Russia over Ukraine, called on Sunday for serious international dialogue to resolve tensions and urged both sides to avoid an armed conflict.

       He said he was praying for "dear Ukraine, for all its churches and religious communities and for all of its people, so that tensions there are resolved through a serious international dialogue and not with weapons".

       "Weapons are not the path to take. May this Christmas bring peace to Ukraine," the pope told thousands of people in St. Peter's Square for his noon blessing and address.

       Ukraine is predominantly Orthodox Christian, with Catholics of either the Latin Rite or Byzantine rite making up about 10%percent of the population in the former Soviet republic.

       U.S. President Joe Biden said on Saturday he had told Russian President Vladimir Putin that Russia would pay "a terrible price" and face devastating economic consequences if it invaded Ukraine.

       Ukraine has accused Russia of massing tens of thousands of troops in preparation for a possible large-scale military offensive.

       Russia denies planning any attack and accuses Ukraine and the United States of destabilising behaviour, and has said it needs security guarantees for its own protection.

       (Reporting by Philip Pullella; Editing by Gareth Jones and Frances Kerry)