Irish premier Leo Varadkar has said Brexiteers need to acknowledge that they created the difficulties surrounding the Northern Ireland border.
The Taoiseach said that he is trying to resolve the issue and ensure that Northern Ireland can retain the "peace and freedom of movement" it has had for the past 20 years.
Speaking on his arrival at the European Summit in Brussels ahead of Brexit negotiations, Mr Varadkar said: "My message to all of the people in Northern Ireland is, what we want to continue on the island of Ireland is exactly what we had for the last 20 years, which is peace and freedom of movement and free trade between Northern Ireland and Ireland and indeed between Ireland and Britain."
He added: "What is disrupting that is Brexit and I would hope that some of the people who supported Brexit and campaigned for that would realise, or at least acknowledge, that they are the ones who created this problem and I am one of those people who is trying to resolve it, trying to retain what we have had for 20 years ... That's what I am working towards."
Mr Varadkar said he is happy with the "maintain full alignment" agreement that was made last week.
"In this backstop scenario the UK and Northern Ireland in particular would maintain full alignment with the rules and regulations of the internal market and customs union.
"That gives us a very strong assurance that there won't be a hard border on the island of Ireland," he added.
Mr Varadkar said that while there are those who want to "spin" what was agreed for their own "political reasons", the language of the agreement is "pretty clear".
Speaking about the meaning of full alignment, he said: "Our view is [the Joint Report] is very strong language. Maintain means 'keep as it is' of course. Full means 'full' not 'partial' and alignment means 'keep in line'."
Earlier Ireland's Foreign Affairs Minister Simon Coveney said that a Brexit transition period needs to be closer to five years than two.
Speaking in the Dail on Thursday Mr Coveney insisted that businesses need time to adapt to any new realities in the context of Brexit.
He also said that, in his view, the commitments that the UK Government has made to Ireland and the rest of the EU are "cast-iron".
Mr Coveney was referring to comments by UK Brexit Secretary David Davis earlier this week that the breakthrough Brexit deal was not legally binding, but rather "more a statement of intent".