Melbourne Archbishop, Denis Hart, says Pope Benedict XVI is right to resign because of his age.
He rejected the view that the Pope had promised a lot but delivered little during his time as head of the church - as some victims of child sex abuse by clergy are arguing.
'You've got to think of what a man in his high-70s and 80s is able to do, particularly when he comes to (being) the head of a big organisation,' Archbishop Hart said.
'I'm not excusing these things but it becomes increasingly difficult for him to face these things because of his age and frailty.'
He said Pope Benedict had been terribly upset by the awful things that had happened and in 2001 had reformed the procedures of the congregation for the doctrine of the faith - the department that has the power to bring priests to justice within the church system.
Archbishop Hart said the College of Cardinals would select the best candidate to lead on a range of fronts, from engaging with society to being an ambassador for peace.
'I wouldn't exclude an African, a South American and Asian or they may go back to having an Italian, who knows,' the archbishop said.
'I'm sure the focus has to be who can lead the church, who will inspire the people, who will teach us and guide us, make us holy and make us reach out to each other.'
Archbishop Hart was with the Pope in Rome in January and said he seemed frail.
'I think Pope Benedict has the focus absolutely correct because he realises the frailty of age means that he can't do the job and he's said that,' he said.
'In the modern world where things are moving so much faster, where there's so much change, obviously we want to have someone to lead the church who really can gather us together, teach us and reach out into the world.'
He said Pope Benedict won't just fade but will spend his time praying for the church and will be remembered for his writing and his teaching.
He said he shouldn't be judged on how he responded to individual issues, but how he led the church on the whole.
Whoever is elected to succeed Pope Benedict will have a 'super-human' task ahead of him, Archbishop Hart said.
'The role is so huge and all-embracing we shouldn't focus on one or two particular items but look at it as a holistic way.'
'It's a huge, momentous task. A superhuman task.'