Barack Obama will travel to Orlando on Thursday to pay his respects to the families of the victims of Sunday's gun massacre which left 49 people dead.
Last night people around the globe - including here in Ireland - held vigils for those killed in a show of defiance against terrorism.
The US President has described the mass shooting as an attack on all Americans - but said there is no clear link to so-called Islamic State.
However Mr Obama has said the attack is being treated as a terror investigation: “It appears that the shooter was inspired by various extremist information that was disseminated over the internet.
“All those materials are currently being searched, exploited so we will have a better sense of the pathway that the killer took.”
Here at home the national flag will fly at half mast today in memory of the victims of the Orlando nightclub shooting.
The Government has announced the measure as a mark of respect to those who died.
Flags will be lowered at Leinster House and all departmental buildings.
Meanwhile, in Limerick, Limerick Council is opening an online book of condolence this morning for the victims of the Orlando shooting tragedy.
49 people were killed and 53 injured when a gunman opened fire at a gay nightclub in the city in the early hours of Sunday morning.
People are being invited to pay their respects on Limerick dot ie, forward-slash council.
Mayor of Limerick Liam Galvin, says it is the least they can do.