Taoiseach Enda Kenny has said that Britain remaining in the European Union is a critical issue for Ireland.
Mr Kenny is meeting British Prime Minister David Cameron, as part of Mr Cameron's negotiations across Europe on EU reform.
At a joint press conference with Mr Cameron, Mr Kenny said that if Britain does leave the EU it would create serious difficulties for Northern Ireland.
Britain's only land border with the EU is between Northern Ireland and the Republic and there are fears a British exit from the bloc could damage trade and inflame political tensions.
He also said that he believes all of Britain's demands for EU re-negotiations are solvable.
Mr Cameron is pushing for a reform deal ahead of the forthcoming British referendum on EU membership.
While a date has not been set for the vote, Mr Cameron still hopes to reach agreement on a reform package at next month's EU summit.
Mr Kenny said he was hopeful a deal to keep Britain within the bloc could be sealed next month.
That would clear the way for a ballot - potentially as early as June of this year.
In the past Mr Kenny has said that Ireland could be a key ally to Britain in getting the changes it wants in Europe.
The Government has also said it does not want to see Britain leave the EU, a view held by Mr Cameron although he has said he will not advocate a vote one way or the other until he has completed his European negotiations.
This morning the Taoiseach met British and Irish business leaders.
Cameron invited to visit for 1916 commemorations
Meanwhile, Mr Kenny has invited Mr Cameron to visit Ireland for the commemorations of the 1916 Rising.
Mr Kenny said he invited Mr Cameron to "come over" if he feels it is "appropriate, and obviously he will consider that in due course".
Mr Cameron acknowledged the anniversary of "important events in our shared history".
"We'll mark them, as we should, in a spirit of mutual respect, inclusiveness and friendship," he added.
Suggestions last year that a member of the British Royal family could be invited to take part in the main State celebrations provoked an outcry.
The proposal was then binned and a decision taken that will see Dublin-based ambassadors as the only representatives of foreign governments asked to attend events on Easter weekend.
However, Minister for Arts, Heritage and the Gaeltacht Heather Humphreys has since hinted the Prince of Wales could be invited to some of the peripheral events.
Two weeks ago, Mr Kenny declared his disappointment in Northern Ireland's new First Minister Arlene Foster's plans to snub commemorations.