Many Anglicans are hopeful that Rome will allow groups who convert to Catholicism en masse to maintain elements of their current identity.
At a meeting with cardinals from around the world, the Pope discussed the growing splits between liberals and conservatives on issues such as the ordination of women and openly homosexual bishops.
In an apparent appeal to Dr Rowan Williams, the Archbishop of Canterbury, a senior Roman Catholic called for Anglican leaders to resolve the matter urgently.
Cardinal Walter Kasper, the president of the Pontifical Council for Christian Unity, said: “They cannot postpone all this crisis. There must be a decision made. But it is not in our hands.”
The cardinal was more optimistic about the prospects of healing the 1,000-year-old schism between the Catholic and Orthodox Churches following a “breakthrough” meeting in Ravenna earlier this month.
A joint document, issued after the meeting between leaders of the two faiths, acknowledged that the Pope had primacy over all bishops but did not agree upon what legal authority that gave him.
The meeting of cardinals took place as the Vatican announced that the Pope would soon publish his second encyclical, on the theme of “Christian hope”.
The 81-page letter will exhort Christians not to be afraid in the face of world upheavals, violence, rapid change and “human dramas”, but rather to embrace “hope founded on faith”.