A new national stadium at the Maze will proceed if an alternative is not proposed by the end of this month, the minister in charge has insisted.
How the Maze site could look if the plans get the go ahead
Edwin Poots said the process "cannot go on indefinitely".
The plan is for a 35,000-seater stadium for soccer and rugby, and the provision of more seats for GAA fans.
Mr Poots, the minister for Culture, Arts and Leisure, met developers proposing a Belfast site, but was not satisfied that their plans were viable.
He said the Maze/Long Kesh Site was the only site able to accommodate "a potentially viable shared Stadium for all the sports involved - soccer, rugby and gaelic games".
He added: "A multi-sports stadium must be delivered to meet the 2012 Olympics timetable, it must be supported by the governing bodies of the relevant sports, be economically viable and be consistent with government's wider objectives of a shared future."
However, Belfast City council and one of the developers behind a proposed new stadium have said there are viable plans for an alternative site to the Maze.
It said there must be a fair and transparent process and that the minister has to create a level playing field for everyone involved.
Demolition of the Maze site is expected to be completed in November.