Several men who were sexually abused by a priest in Chile have described private talks they have held with Pope Francis at the Vatican over the weekend as very helpful and respectful.

James Hamilton, one of three clergy abuse survivors whom the pope invited to Italy, wrote on Twitter that his conversation with Francis, which lasted more than two hours, was 'enormously constructive'.

A second survivor, Jose Andres Murillo, tweeted that he had stressed the importance of understanding sexual abuse as 'abuse of power' during his time with the pope.

The third victim, Juan Carlos Cruz, wrote: 'I spoke for more than two and a half hours alone with Pope Francis. He listened to me with great respect, affection and closeness, like a father. We talked about many subjects. Today I have more hope in the future of our church... Even though the task is enormous.'

I spoke for more than two and a half hours alone with Pope Francis. He listened to me with great respect, affection and closeness, like a father. We talked about many subjects. Today I have more hope in the future of our church... Even though the task is enormous.

— Juan Carlos Cruz Ch. (@jccruzchellew) April 29, 2018

Pope Francis has performed a spectacular reversal over the claims. During a January visit to Chile, he appeared to dismiss claims that a bishop, Juan Barros, covered up their abuse, calling the victims' assertions 'calumny'. He then ordered a Vatican-led investigation and wrote an extraordinary letter on April 11 admitting to 'grave mistakes' in the handling of the affair.

According to the Associated Press, the pope has requested the Holy See not to reveal the contents of his talks with the abuse victims, saying his priorities were listening to them and asking for their forgiveness.

AP reported that on Sunday, as some 30,000 people gathered in St Peter's Square for the pope's customary noon appearance, the three men, looking relaxed, stood on a terrace overlooking the square and waved to well-wishers.

Cruz said in a tweet he was happy to see that his friends were 'calm and in peace and feeling very welcome by the Holy Father' after their visits with Francis.

The three men visiting the Vatican were abused by the Fr Fernando Karadima. Their testimony was decisive in the Vatican's decision to remove Karadima from ministry and to order him in 2011 to undergo a lifetime of penance and prayer.

The men have repeatedly asserted that Barros witnessed Karadima abusing them and did nothing to stop the abuse, a claim that Barros denied.

Earlier this month, Cruz said that he would demand that the pope fires 'toxic' bishops and that strong papal action in Chile would send a long-overdue message to the entire Church.

Cruz told Reuters in an interview: 'I would say "hold these bishops accountable, fire a few of them, if not many of them, but fire them and not give them a cushy job here at the Vatican."'

He added: 'Like in a company [I would say] "you need to be preparing your resumé". That's what I would say to these bishops.'

Barros and other bishops were put under the spotlight in January when the pope sent one of the Vatican's most experienced sexual abuse investigators, Archbishop Charles Scicluna of Malta, to New York and Chile to talk to victims and bishops.

Scicluna produced a 2,300-page report, which prompted the pope to call next month's meeting.

Cruz said he hoped the pope would take decisive action in order to 'send a message to the world that Chile is an example of what's going to happen all over if this culture of abuse and cover up continues'.

He said he was confident that some good would come out of his meeting with the pope.