The Taoiseach has said some checks on goods and animals may need to be carried out near the border in the event of a no-deal Brexit.
Addressing the British Irish Chamber of Commerce Dinner in Dublin on Thursday night, Leo Varadkar said as far as possible, these checks will take place near ports and airports.
"There will be checks on goods and on live animals and as far as possible, these will take place near the ports, airports and at business level but some may need to take place near the border.
"We're working out the details of this with the European Commission and we'll inform the public and businesses as soon as we know what the outcome will be," he said.
Mr Varadkar told the audience there is a "significant and growing" risk of a no-deal Brexit - something the Irish government doesn't want to see.
"We don't want to see a no-deal, and we will continue our efforts to avoid one to the very end. But not at any cost," he said.
He said the story of Brexit is not going to end whether the UK leaves the EU on October 31 or January 31.
"There is no such thing as a clean break. Rather, we just enter a new phase."
Mr Varadkar said Brexit represents a permanent change for the political and economic environment of the EU and the UK.
"Recently Prime Minister Johnson and I spoke by phone. we spoke of our shared desire to see the Northern Ireland political institutions reinstated, and we shared our perspectives on the Withdrawal Agreement and agreed that our teams would establish one to one contact and we'll meet again in Dublin on Monday.
"Unfortunately though, given the political developments in the UK there is a significant and growing risk of no-deal. We don't want to see no-deal and we'll continue our efforts to avoid one until the very end but not at any cost," he said.
"We are open to alternatives, we always have been, but they must be realistic, they must be legally binding and they must be workable in practice.
"Sadly we've received no such proposals to date," he said.
"Unlike some, I see no upsides to no-deal and yes I do fear it - but I'm prepared for it politically."