The Irish premier has warned the UK Government there can be no back-sliding over the Brexit agreement on Northern Ireland.
Taoiseach Leo Varadkar said the Irish Government will continue to "advance and defend" Ireland's interests and "seek to mitigate the negative effects of Brexit for the country".
Referring to the last-minute deal UK Prime Minister Theresa May struck with the EU in December Mr Varadkar said: "There can be no back-sliding."
During Brexit negotiations in December the UK Government agreed that any future deal must protect "North-South co-operation" in Ireland and hold to the UK's "guarantee of avoiding a hard border" on the island.
The agreement also said that "no new regulatory barriers" would be allowed between Northern Ireland and the rest of the UK, and Northern Ireland's businesses would continue to have "unfettered access" to the UK internal market.
Speaking in the Dail on Tuesday Mr Varadkar said: "It will be important to remain vigilant to ensure that commitments entered into in December are delivered in full."
However, Fianna Fail leader Micheal Martin warned that the agreement does not mean the absence of a border on the island of Ireland.
"I am very concerned about the basic contradiction within the agreement about the introduction of no economic divisions on this island," he said.
Mr Martin added: "The final text repeats the assertion of the UK Government from very early about its intentions to avoid new barriers.
"This is contradicted by its new statement that all parts of the UK will be treated exactly the same. What is being discussed is a differently managed border. Not the absence of a border."
The opposition leader hit out at Mrs May's administration saying it was "ridiculous it took 18 months for the UK Government to recognise the reality that it no longer had the ability to intimidate the European Union by threatening a barrage of tabloid headlines and a possible veto".
Earlier the Taoiseach said contingency planning is continuing for all possible scenarios during the Brexit transition period.
Mr Varadkar said: "The House can be assured that, as we have done up to now, in the negotiations, the Government will continue to advance and defend Ireland's interests and to seek to mitigate the negative effects of Brexit for the country and exploit any opportunities."