Pope Francis has warned US Catholic bishops they need to deal with the issue of sexual abuse that has devastated the church there.

The bishops are meeting for a spiritual retreat directed by the Preacher to the Papal Household, Fr Raniero Cantalamessa.

In his 3,600-word letter, Francis tells the bishops: 'Combating the culture of abuse, the loss of credibility, the resulting bewilderment and confusion, and the discrediting of our mission urgently demands of us a renewed and decisive approach to resolving conflicts.'

He says the US Church has been 'shaken' by scandals. 'The Church's credibility has been seriously undercut and diminished by these sins and crimes, but even more by the efforts made to deny or conceal them,' he adds. 'This has led to a growing sense of uncertainty, distrust and vulnerability among the faithful. As we know, the mentality that would cover things up, far from helping to resolve conflicts, enabled them to fester and cause even greater harm to the network of relationships that today we are called to heal and restore.'

He urges bishops to cultivate a 'spirit of discernment' so their actions may have the 'flavour of the gospel'.

'Loss of credibility calls for a specific approach, since it cannot be regained by issuing stern decrees or by simply creating new committees or improving flow charts, as if we were in charge of a department of human resources,' he says. 'That kind of vision ends up reducing the mission of the bishop and that of the Church to a mere administrative or organizational function in the "evangelization business".'

In a striking image, he says: 'Clearly, a living fabric has come undone, and we, like weavers, are called to repair it.' He calls for 'not only a new approach to management, but also a change in our mind-set (metanoia), our way of praying, our handling of power and money, our exercise of authority and our way of relating to one another and to the world around us'.

He urges the Church to abandon defensiveness and to 'stop projecting onto others our own confusion and discontent, which are obstacles to unity'.

In a direct challenge to the Church's leaders, many of whom have faced fierce criticism over their handling of sexual abuse allegations, he says: 'In a word, a new ecclesial season needs bishops who can teach others how to discern God's presence in the history of his people, and not mere administrators. Ideas can be discussed but vital situations have to be discerned.'