Archbishop of Canterbury Rowan Williams and a top Catholic prelate prayed Friday for Christian unity amid tensions over the Vatican's recent overture to Anglicans to join the Catholic fold.

Basing his homily on the Lord's Prayer, the Church of England's spiritual leader said it evoked a "spirit of communion" and led "to a prayer of forgiveness and reconciliation."

He added - As we pray for unity between Christians... surely part of it is (asking God to) give us the grace to be givers of your gift to one another, that we may meet one another's hunger, that we shall share the love of God together. -

Cardinal Walter Kasper, head of the Vatican's Pontifical Council for Promoting Christian Unity, presided over the evening prayer attended by some 200 people in the intimate setting of a Jesuit oratory in Rome.

Williams was to meet Pope Benedict XVI on Saturday just two weeks after the Vatican unveiled the new framework for the conversions, aimed at Anglicans who oppose the ordination of women as well as openly gay clergy.

The British press has painted Williams' visit, though scheduled long before the controversy, as a "showdown" between the two churches amid accusations that the Vatican presented the Church of England with a fait accompli.

Although the pope's initiative was announced simultaneously in Rome and London and hailed in a joint communique by the two men, Williams himself said he was informed of the move "at a very late stage."

The Anglican leader later concluded that it was - in no sense at all intended to undermine existing relations between our two communions or to be an act of proselytism or aggression. -

Williams, in a speech at Rome's Gregorian University late Thursday, insisted the "glass is genuinely half-full" in relations between the two churches while acknowledging they had "unfinished business" to resolve.

The Anglican leader is in Rome for celebrations of the 100th anniversary of the birth of Johannes Willebrands, a Dutch cardinal who was a pioneer in Catholic ecumenism.