A recent agreement established that Northern Ireland remains part of the United Kingdom, with any change in status requiring a public vote.
This arrangement was formalised under the political deal signed on 10 April 1998 to end decades of conflict in the region.
The document states the secretary of state must organise a referendum if it seems probable that most residents would support unification with Ireland.
However, the text does not specify how officials should determine whether such majority support exists.
Micheál Martin has stated this lack of detail is unsatisfactory for the current situation.
He emphasised the shared island initiative has already delivered over €1bn in funding for cross-border projects since its inception.
Critics within his own party are calling for a firmer approach regarding the timing and method of any future poll.
Debate continues on whether the vote should follow general principles or await specific plans for governing a united state.
The Good Friday Agreement created a power-sharing government representing both nationalist and unionist communities in Derry City and Strabane District Council areas.
It was ratified by voters in both Northern Ireland and the Republic of Ireland before being implemented.
Martin suggested greater clarity is needed on the criteria used to judge potential majority support.
He noted that while no fixed timeline exists, a new poll cannot occur if one has been held within the previous seven years.
The secretary of state retains the authority to decide when to hold the referendum based on their assessment of public opinion.
No further details were provided on how this judgement call will be exercised in practice.
The outcome of any future vote would determine whether Northern Ireland's constitutional status changes.
Current discussions remain focused on balancing democratic principles with the stability of the peace process established in 1998.