Northern Ireland Secretary Chris Heaton-Harris has said he is “quite convinced” football fans will back Casement Park as a Euro 2028 venue.
His comments came after Irish Football Association (IFA) chief executive Patrick Nelson said there is “no funding opportunity” to expand Windsor Park as an alternative venue for matches.
European football’s governing body, Uefa, confirmed last month that the UK and Ireland will jointly host the tournament.
As part of the successful bid, the west Belfast GAA stadium has been listed as one of the stadiums where matches will be played.
But the site is currently derelict and plans by the GAA to redevelop it with a 34,000 capacity have been mired in controversy and hit by delays.
During Northern Ireland’s recent match against San Marino at Windsor Park, a number of fans chanted in opposition to games being played at Casement.
But Mr Heaton-Harris told the BBC that playing Euro 2028 matches at Casement would secure a “strong legacy plan” for the stadium.
He said: “I am actually quite convinced that football fans in Northern Ireland will get behind Casement Park.
“I’m pretty sure that, when it’s built, it will sell out in the Euros and beyond.
“Whenever people see what can be done there I think we’ll be in a good space.”
The Casement project has been been delayed by a series of legal challenges and is further complicated by the lack of a functioning Executive at Stormont.
The redevelopment has also been hit by rising costs, with an original projected price tag from almost a decade ago of £77.5 million now believed to have spiralled to well above £100 million.
The GAA is part-funding the project but has yet to reach an agreement with Stormont on how to cover a multimillion-pound shortfall.
Unionists have expressed concern about further public money being committed to the project, while Taoiseach Leo Varadkar has said the Irish Government would be prepared to foot some of the bill.
Gary McAllister, chairman of the Amalgamation of Northern Ireland Supporters’ Clubs, has written to the IFA asking if consideration has been given to allowing a temporary increase in capacity at Windsor Park to allow Euro 2028 matches to be played there.
The Northern Ireland football team play at the National Stadium at Windsor Park in Belfast. However that stadium has a capacity of 18,500 – significantly short of the 30,000 minimum required for hosting games at the Euros.
Mr McAllister has asked what would happen if Casement Park is not completed within the required timescale to meet the Uefa deadline.
He has also asked what consideration has been given to the “logistical and safety issues that may arise given the divided nature of Northern Ireland society”.
In his response, Mr Nelson said: “There is no current funding opportunity from Government for any extension to the National Football Stadium at Windsor Park.
“The national stadium at Windsor Park is our home and a place we are proud of, but there is no route to fund an expansion.
“The alternative to the route we have chosen was not to have any ambition for Northern Ireland football and decline to be part of the bid.
“The matter of the funding for Casement Park is a consideration for Government.”
He added: “The planning for the access and egress of fans to stadia (Casement Park) will be given every consideration with governmental partners and the PSNI.
“There is no question it will be overlooked and we will work closely and diligently on all aspects of this.
“This is a pivotal moment for football and society in this country.
“The Irish FA and the Amalgamation can be crucial in playing a positive role in this.”