US President Barack Obama will address the Republic from a rally at Croke Park during his flying visit to Ireland on May 23.

Mr Obama will also stay in the capital overnight after his whirlwind tour of Dublin and Offaly. His security team is finalising his itinerary, which includes a trip to Croke Park where he will make a speech to the nation from the famous GAA stadium before heading onwards to Moneygall, Co Offaly.

He will then return to Dublin where he will stay before heading to Britain the next day.

Mr Obama's visit is due to take place on Monday, May 23. But sources said there is still a possibility of switching the date of the visit to Sunday, May 22, depending on the president's schedule.

Mr Obama's team is concerned that it might prove too difficult to fill Croke Park on a Monday, and that Sunday would be a better day.

It is not yet clear if the stadium event will be ticketed, or whether people can simply turn up on the day.

But it is understood that anyone attending the event will be screened by an army of Irish and US security officials.

Mr Obama's security detail has already checked out Lawton House in Moneygall, which is owned by Health Minister James Reilly, as a possible landing site for the presidential helicopter.

It is not yet known how many hours Mr Obama will spend in his Co Offaly ancestral home, but it is believed that this will be decided tomorrow when Offaly county manager Pat Gallagher meets the American ambassador, Dan Rooney, to discuss the arrangements in detail.

Former Taoiseach Brian Cowen is expected to be asked to play an official role in welcoming Mr Obama to Moneygall.

Mr Cowen was the first person to extend an invite to the US president to visit Offaly.

Meanwhile, Marie MacDonogh, the daughter of the late author Stephen Mac- Donogh, who wrote 'Barack Obama -- The Road From Moneygall,' has been asked to present Mr Obama with a copy of the book during his visit.

The book contains details of Barack Obama's family tree, which can be traced all the way from the president's mother back to the Kearney family in Moneygall.

Mr MacDonogh spent months in the US researching the book, which describes how Thomas Kearney from Moneygall emigrated in the 1780s to Maryland, USA.

A year later his son, Falmouth, followed him as did the rest of his family from Moneygall. Falmouth Kearney was Barack Obama's great great great grandfather.

Mr Obama will be brought to the Kearney homestead, which is now vacant, on Moneygall's Main Street, where he will be asked to unveil a plaque.

It is understood the nearby village of Shinrone, where the Kearneys originally hailed from before later settling in Moneygall, will also be given recognition during the presidential tour.

Villagers in Moneygall were in overdrive yesterday as preparations continued ahead of the May stopover.

Contractors replaced pavements in the area and fresh paint is due to arrive next week.

A booklet is also being made by locals to commemorate the visit and to detail the history of Barack Obama's Irish roots.

Meanwhile, new research published in the 'New York Times' has revealed First Lady Michelle Obama also has Irish roots.

Megan Smolenyak -- the genealogist who uncovered the Moneygall connection to Mr Obama traced Mrs Obama back to young slave girl Melvinia Shields. Melvinia went on to have children with an Irish-American slave owner named Shields.