Casement Park can be redeveloped for a figure of around £260m, according to GAA president Jarlath Burns.
The former GAA ground in west Belfast has been closed for over a decade amid delays to regeneration plans.
The Stormont Executive committed to redeveloping Casement Park in 2011 as part of a strategy to revamp football's Windsor Park and the rugby ground at Ravenhill.
While the two other Belfast-based projects went ahead, the redevelopment of Casement was delayed because of legal challenges by local residents.
A proposal to rebuild Casement as a venue for the Euro 2028 games collapsed last year when the UK government said it would not bridge a funding gap to deliver the project in time.
It said the risk to the public purse of missing the tournament deadline was too high and expressed concerns about how the cost of the project had potentially risen to more than £400m.
However, speaking this afternoon after meeting Sinn Féin representatives in Stormont, Burns put a cost of £260m (€312m) on the new Casement and said that this figure had been provided to Communities Minister Gordon Lyons
"We think we can build it for around £260 million," Burns said. "That figure is a figure that has been given to the minister, including all the contingencies and unforeseen circumstances that might arise.
"We remain very, very committed to Casement Park being built, to becoming the stadium for Gaelic Games in Ulster."
After the meeting, Sinn Féin urged the UK government to "stop dithering" and "fulfil its pledge" to help fund the rebuilding at the venue.
Sinn Féin vice president Michelle O'Neill, along with Senator Conor Murphy and West Belfast MP Paul Maskey had met a delegation from the GAA, which included Burns along with senior figures from Ulster GAA.
Speaking afterwards, Mr Murphy said Sinn Féin reaffirmed its "full support for the transformative rebuild of Casement Park".
He said while the executive, GAA and the Irish Government have set out their contributions to fund the building of the stadium, the onus is now on the UK's government to do the same.
He said the rebuild has "huge potential to create jobs, boost tourism and be an economic driver for west Belfast and further afield".
"For too long, the British government and the communities minister have dragged their heels and failed in their commitment to help fund Casement Park," he said.
"This dithering must end, and previous funding pledges fulfilled.
"The Labour government should now clarify the funding it will allocate for the reconstruction of this stadium and enable us to move forward and build a new home for Ulster gaels.
"Sinn Féin will ensure Casement Park is built, and we will continue to work alongside the GAA and others to deliver this exciting and game-changing project."
The Northern Ireland Executive committed £62.5m in 2011 to the Casement project.
The Irish Government has offered roughly £42m and said this funding remains in place even without the stadium being built for the Euros.
The GAA has pledged to contribute £15m.
It has been reported that the cost of the project has fallen to £270m since it was confirmed the ground would not host Euro matches, still leaving a funding shortfall of about £150m.
