Pope Francis is expected to make the first papal visit to Ireland in almost 40 years.
The Pontiff is due to attend the next World Meeting of Families, which he said would be held in Dublin in 2018.
The gathering is one of the most high-profile events for the Catholic Church globally, and usually involves a visit by the serving Pontiff.
Pope Francis made the announcement last night at an outdoor Mass for one million people attending this year's World Meeting of Families in Philadelphia as he ended his historic trip to the US.
Earlier, Archbishop Eamon Martin, the head of the Catholic Church in Ireland, told the Irish Independent he was expecting an answer to an invitation issued to the Pope to visit Ireland "very, very soon".
The first and only papal visit to Ireland took place in 1979, when hundreds of thousands of people saw Pope John Paul II as he visited Dublin, Knock, Limerick, Drogheda and Galway.
Archbishop Martin, who attended the National Eucharistic Congress in Knock at the weekend, said: "We have urged [Pope Francis] to come. We have told him that we are really open to a visit and we're hoping that he will answer us very, very soon."
The Pope's representative in Ireland, Papal Nuncio, Archbishop Brown, commented: "It is my fervent hope that the possibility of the Pope visiting Ireland will be realised."
"Pope Francis is well aware that many people in Ireland would love for him to come and visit."