The Government are engaging in "constructive" discussions with the Organisation for Cooperation and Development on corporation tax, the Taoiseach has said.
Ireland was not on the list of signatories to the proposals but remains part of the tax reform process.
Minister for Finance Paschal Donohoe launched a public consultation on the proposals to reform international corporate tax rules in the wake of the OECD announcement.
Speaking in New York, at the start of a five-day visit to the United States, Micheál Martin said the Government want "certainty and continuity" around taxation.
At a joint press conference with the New York Governor, Kathy Hochul, Mr Martin was asked if Ireland remained committed to its 12.5% corporate tax rate.
"I am not going to be making commitments one way or the other to any companies," the Taoiseach said.
In a follow-up interview, Mr Martin was asked if he could no longer guarantee that Ireland's tax rate would remain at 12.5%.
"We're in negotiations at the moment, we are, I mean, 12.5% is our rate, but there's discussions under way within the OECD. So we have made it very clear from the outset that we are engaging in the OECD process in a constructive way and we want certainty, and we want continuity," he said.
"We're not in a position right now when we’re in discussions, we’re involved in a process, this isn’t about guarantees around specifics," he said.
"There is still a journey to travel on this," he added.
Meanwhile the EU's Economy Commissioner has said he is confident there is "a chance to find a shared way" that would see Ireland sign up to the global tax agreement.
Paolo Gentiloni said he knows how challenging the issue is for Ireland.