The pope and the Archbishop of Canterbury said yesterday that “serious obstacles” blocked the way to unity between their churches, a blunt acknowledgment of Vatican disapproval of female priests and an openly gay bishop in the Anglican Church.

Pope Benedict XVI and Rowan Williams made the admission in a joint declaration that they signed during an audience in the Vatican that committed them to continue talks and cooperate on practical issues but underlined the difficulties.

The declaration expressed gratitude for efforts so far at achieving unity, a process that began in earnest 40 years ago after an historic meeting between Mr. Williams’s predecessor, Archbishop Michael Ramsey, and Pope Paul VI.

But it added: “At the same time, our long journey together makes it necessary to acknowledge publicly the challenge represented by new developments, which, besides being divisive for Anglicans, present serious obstacles to our ecumenical progress.”

The pope was even more pointed in an address to Mr. Williams, referring to the “strains” facing the worldwide Anglican Church, which is struggling to contain its divisions over homosexuality.

The consecration by the American branch of Anglicanism of Gene Robinson as its first openly gay bishop in 2003 has brought the 70-million-strong Anglican church to the brink of schism.

The pope told Mr. Williams: “Recent developments, especially concerning the ordained ministry and certain moral teachings, have affected not only internal relations within the Anglican Communion but also relations between the Anglican Communion and the Catholic Church.

“We believe that these matters, which are presently under discussion within the Anglican Communion, are of vital importance to the preaching of the Gospel in its integrity and that your current discussions will shape the future of our relations …

“It is our fervent hope that the Anglican Communion will remain grounded in the Gospels and the Apostolic Tradition which form our common patrimony.”