The Pope has warned that the world faces ruin if selfishness prevails over solidarity during the present economic crisis.

Pope Benedict XVI, following in the tradition of his predecessor, the late Pope John Paul II, who made the principle of subsidiarity in world affairs a cornerstone of his papacy, called for a "spirit of authentic solidarity" to be embraced to enable people in all nations, rich and poor, to be helped.

And he joined other religious leaders in focusing attention on Zimbabwe in particular, where he said people were "trapped for too long in a political and social crisis which, sadly, keeps worsening".

Delivering his traditional Christmas Day message, Urbi et Orbi or "to the city and the world" from the balcony of St Peter's, where many thousands had gathered to hear him speak, he said the "heart of the Christian message is meant for all men and women".

In a clear reference to the present economic uncertainty, he said the Christian message applied to "wherever an increasingly uncertain future is regarded with apprehension, even in affluent nations".

He said: "In each of these places may the light of Christmas shine forth and encourage all people to do their part in a spirit of authentic solidarity. If people look only to their own interests, our world will certainly fall apart."

Benedict said he hoped the light of Christmas would radiate to places where "the basics needed for survival are missing."

He said God's saving grace could "alone transform evil into good" and "change human hearts, making them oases of peace."

And he went on to recite a litany of the world's woes.

Besides Africa and Zimbabwe in particular, the Pope also referred to war-ravaged Kivu, in the Democratic Republic of Congo, and to Darfur in Sudan. In Somalia, he said, people are weighed down with "interminable sufferings" as "the tragic consequences of the lack of stability and peace."

Benedict spoke of violence and tensions in the Middle East as well, lamenting that "the horizon seems once again bleak for Israelis and Palestinians."

He denounced what he called the "twisted logic of conflict and violence" and said he hoped dialogue and negotiation would prevail to find "just and lasting solutions to the conflicts troubling the region."

Benedict also cited Lebanon and Iraq.

Without naming any particular groups, the pontiff called for an end to "internecine conflict" dividing ethnic and social groups and disrupting peaceful coexistence. He also denounced terrorism "wherever" it continues to strike.