A referendum is to be held on whether to allow Irish citizens living abroad to vote in presidential elections.
The move, if passed in a referendum, will see the numbers entitled to vote increase by hundreds of thousands and possibly millions.
Among those who will be able to participate in choosing the president are Irish passport holders in Northern Ireland.
While a date has not being set for the referendum, Taoiseach Enda Kenny confirmed the Cabinet has formally decided to hold one.
Speaking in Philadelphia, Mr Kenny said: "Today's announcement is a profound recognition of the importance that Ireland attaches to all of our citizens, wherever they may be.
"It is an opportunity for us to make our country stronger by allowing all of our citizens resident outside the State, including our emigrants, to vote in future presidential elections."
President Michael D Higgins's seven year term ends next year, with an election likely in October or November 2018.
The Government's decision is in line with the recommendations of the Convention on the Constitution, in their fifth report.
In a statement the Government said extending the franchise in presidential elections to Irish citizens resident outside the State gives rise to a range of legal, policy and practical issues.
An 'Options Paper' will be published later this month to set out the range of options available to give effect to the recommendation of the Convention on the Constitution.
This paper will also be one of the topics for discussion at the Global Irish Civic Forum which will take place in Dublin in May.
Mr Kenny told an audience at the Irish Famine Memorial in Philadelphia that changing the voting system will involve significant work to determine new eligibility rules, to draw up legislation and to implement a new electoral register and new voting procedures for all of our citizens.
"It is appropriate that this announcement is being made here in Philadelphia, where the Irish have made such a mark over the centuries.
"There is no more fitting time or place, as we look forward to our worldwide celebration of St. Patrick's Day and of all that is Irish," he said.
The Government has agreed that work will immediately commence on updating the voter registration process.
"This decision by the Government is a clear recognition of the importance that Ireland attaches to her citizens, wherever they may be.
"You are part of who we are as a people, what we have done and where we have gone in the world.
"We will make that connection ever stronger for the future," the Taoiseach concluded.