"The twenty-first century is witnessing a weakening of the power of nation states, chiefly because the economic and financial sectors, being transnational, tend to prevail over the political," the pope writes in the encyclical letter Fratelli Tutti (Brothers All), released on Sunday.

"Given this situation, it is essential to devise stronger and more efficiently organized international institutions, with functionaries who are appointed fairly by agreement among national governments, and empowered to impose sanctions," the pope advises in the 43,000-word text.

"When we talk about the possibility of some form of world authority regulated by law, we need not necessarily think of a personal authority," the pontiff asserts. "Still, such an authority ought at least to promote more effective world organizations, equipped with the power to provide for the global common good, the elimination of hunger and poverty and the sure defence of fundamental human rights."

Among the possible candidates for such a role, the pope turns his attention to the United Nations Organization, with which he enjoys close ties.

"In this regard, I would also note the need for a reform of the United Nations Organization, and likewise of economic institutions and international finance, so that the concept of the family of nations can acquire real teeth," Francis declares, citing a text from his predecessor, Pope Benedict XVI.