The country star had been scheduled to perform sell-out gigs at Croke Park from 25 to 29 July.
However Dublin City Council has only granted permission for the concerts on Friday 25, Saturday 26 and Sunday 27 July, leaving the concerts on Monday 28 and Tuesday 29 July in doubt.
A statement issued from the US by Garth Brooks on Thursday evening said: "I can't thank the people of Ireland enough for how welcome they have made me feel.
"I have faith Dublin City Council will make the best decision for the people of Ireland.
"For us, it is five shows or none at all. To choose which shows to do and which shows not to do would be like asking to choose one child over another.
"However this plays out, Ireland has my heart and always will."
Earlier, a statement from Dublin City Council said it would not be appropriate to grant five consecutive nights of concerts at the GAA venue, considering three consecutive One Direction concerts have already taken place from the 23 to 25 May.
It added: "Given that Croke Park is situated in a heavily populated residential area, five shows in a row following on from the three concerts already held there this year is considered an over intensification of use of the stadium for the holding of special events/concerts.
"It would be in effect permitting an increase of 100% in terms of the maximum number of concerts that had previously been held in Croke Park in any given year since the redevelopment of the stadium."
The council said they also took into consideration the "cumulative effect on residents and on some businesses" in the area.
Residents living near Croke Park were last month handed £400,000 in compensation following a row over the upcoming concerts.
The reasons given by the Council in disallowing the fourth and fifth Garth Brooks concerts are equally valid for the first three as well.
Colm Stephens, local Croke Park resident
In reaction to Dublin City Council's decision, local resident Colm Stephens said: "While we welcome the decision by Dublin City Council to refuse a licence for two concerts, the residents in the Croke Park area have always maintained that three a year is more than enough."
He continued: "For decades the residents have been promised by the GAA that Croke Park would consult with us before any such events are announced. This was not the case on this as well as many other occasions.
"Local residents are delighted that DCC has respected their view and accepted the issues raised in their objections in order 'to minimize disruption to the neighbourhood in which the concerts were to take place. If we had real consultation and genuine engagement we could have avoided last minute decisions like this."
The GAA said they "will fully assess the implication" of the announcement and will make no further comment before Monday July 7.
Dublin Lord Mayor, Christy Burke, said: "It was an executive decision made by a City Manager, I have to respect that. It's a decision that I'm sure wasn't taken lightly."
More than 4000,000 tickets for the gigs have been sold.
It has been reported that Dublin's Aviva Stadium is being considered as an alternative venue to host the Garth Brooks gigs on 28 and 29 July.
It has a capacity of 50,000 compared to Croke's 80,000 and it is thought the concerts will be held over three nights to ensure everyone who bought a ticket will be able to attend.