Pope Francis will cross the border to visit Northern Ireland in August 2018, the deputy first minister has said.

Martin McGuinness told journalists: "I've been around a long time and I know how these things work."

He was speaking after Taoiseach (Irish Prime Minister) Enda Kenny broke news of a papal visit to Ireland after meeting the Pope at the Vatican.

A spokesman for First Minister Arlene Foster said if the Pope visited NI as a head of state, she would meet him.

However, at this stage, the Irish Catholic press office has refused to confirm the visit would take place.

Image copyright AP Image caption Pope Francis and Enda Kenny at a meeting in Rome on Monday

Mr Kenny tweeted that the Pope "has been an important voice for the young, the poor and disadvantaged".

"Glad he will visit Ireland in 2018," added Mr Kenny.

"We discussed what he might do and obviously that's a matter for dialogue between His Holiness and the bishops.

"Obviously if that means that he also travels to Northern Ireland we will assist and co-operate in making whatever arrangements."

The Catholic primate of Ireland, Archbishop Eamon Martin of Armagh, said: "We would love to think that if the Pope is coming to Ireland that perhaps he might be able to visit Northern Ireland at the same time.

Archbishop Martin said the visit would be a "deeply symbolic and powerful moment" for those in Northern Ireland, coming after the visit of the Queen and the first state visit of Irish President Michael Higgins to London.

"That would be in my mind completed by a visit by the Holy Father to Northern Ireland, where he will be welcomed by members of all the traditions here," he said.

The editor of the Irish Catholic newspaper said Northern Ireland would be a vital part of Pope Francis' time on the island of Ireland.

"If a visit to the north wasn't included, the Pope would probably skip the whole island," Michael Kelly told Radio Ulster's Talkback programme.

Image copyright Tony Connolly/RTE Image caption Mr Kenny presented the Pope with a print by artist Harry Clarke

He said the Vatican felt a visit north of border would complete the pilgrimage by Pope John Paul in 1979.

At that time, the Pope did not cross the border.

World Meeting of Families

The timing coincides with the World Meeting of Families in Dublin in almost two years' time. Since its inception in 1994, there has only been one occasion when the pontiff did not attend the meeting.

It is understood that the Vatican does not confirm a papal visit until six months before it is scheduled to take place.

Image copyright Tony Connolly/RTE Image caption Mr Kenny was personally welcoming the Pope's decision to hold the World Meeting of Families in Dublin

In an earlier briefing on the World Meeting of Families, the Vatican said the Pope's programme was normally announced just a few months prior to any event.

The Pope had expressed his desire to visit Ireland and such a visit would bring great joy to Irish Catholics and others, said the briefing.

However, given the age of Pope Francis, a visit in 2018 would inevitably have a more restricted programme than that of Pope John Paul II in 1979, it added.

SDLP MLA Alban Maginness told Talkback that things in Northern Ireland had "moved on enormously".

Image copyright Rte Image caption The Irish Prime Minister with the Pope following their discussions in the Vatican

"The Pope will come north and he will be very welcome," he said.

"There is a new mood among Christian believers. The Protestant Churches will be very welcoming. There is a different atmosphere and it will do a lot to excite interest."

Mr Maginness said he hoped the Pope would come to Belfast.

The Evangelical Alliance's David Smyth told Talkback that he had no issue with such a visit, and offered a cautious welcome to it.

"To me, it is an issue of religious freedom," he said. "We say we care a lot about that in Northern Ireland. Not to allow a visit would be strange."