TAOISEACH Leo Varadkar has called for regulatory checks to take place between Great Britain and Northern Ireland at sea ports in Belfast and Larne if there is a no-deal Brexit.
Speaking on RTE Radio One's Countrywide programme he also said any EU country that vetoed a further Brexit extension for the UK would not be forgiven by other member states.
He said he believed the prospect of one of the EU27 saying no to another extension at this week's European Council meeting was "extremely unlikely".
The Irish premier suggested his own preference was for a longer extension than the June 30 date proposed by the UK.
Mr Varadkar also said that, in a no-deal scenario, the "logical" way to ensure a free-flowing Irish border would be for regulatory checks to take place between Great Britain and Northern Ireland at sea ports in Belfast and Larne.
The Taoiseach acknowledged that there was increasing frustration at the Brexit process within the EU27, particularly among countries which were less dependent on trade links with the UK and wanted to focus on other key issues affecting the bloc, such as migration and the next EU budget.
He said he had asked for their "patience and solidarity".
"Today we have got that and I think that will continue," he said.
Mr Varadkar said the prospect of a crash-out Brexit on Friday was unlikely.
"Because nobody wants no-deal I think the likelihood is an extension. But we want to avoid an extension that just allows for more indecision and more uncertainty. So I'd prefer to see a longer extension during which the United Kingdom has more time to decide really what future relationship it wants to have with the European Union, rather than the alternative, which could be rolling extensions every couple of weeks, every couple of months."
He said the UK and Ireland would find themselves in a "dilemma" in the event of a no-deal because they would have to balance obligations under trade rules to check goods and obligations under the Good Friday Agreement to keep the Irish border open.
"It would be up to us to protect the single market and it would be up to the United Kingdom to enforce WTO rules," he said. "We would both find ourselves in a dilemma because, on one hand we would have obligations under the European treaties, they'd have obligations under the World Trade Organisation.
"But then there's the Good Friday Agreement and, to me, that is equally important and the Good Friday Agreement is about the peace process, it's about ensuring we have free movement of people, goods and animals."
Mr Varadkar said Ireland was exploring the possibility of conducting regulatory checks away from the border, potentially on business premises.
He noted that the UK Government's no-deal plan suggested initially treating Northern Ireland differently from Great Britain in terms of tariffs and checks.
"That opens up the potential to have the checks at the ports in Larne and Belfast, which is the logical place to have them of course, not on the land border," he said.
The Taoiseach said he would like the principles behind the Withdrawal Agreement's contentious border backstop to be honoured even if there was a no-deal.
"The reason we came up with the backstop is because it is the solution and, even in the event of a no-deal we will be saying to the UK 'You still have obligations under the Good Friday Agreement, you still committed to full regulatory alignment back in December 2017 and we still want the arrangements that are in the backstop to apply'," he said.