There will be more disruptions and costs on doing business with Britain from today, Foreign Affairs Minister Simon Coveney is warning.
Mr Coveney insisted the worst impacts of a no-deal Brexit have been avoided after a trade deal was struck between the EU and UK just before Christmas.
However, the FG deputy leader said there will still be significant problems for businesses trading with Britain.
"We are going to see more disruption and more delay and therefore more cost on doing business and that's the downside of Brexit," Mr Coveney told the Herald.
"There's no such thing as a Brexit that happens without some disruption or inconvenience because what we're moving to is a far lesser trading arrangement than what we had before," he added.
Mr Coveney said the deal struck by EU chief negotiator Michel Barnier does ensure there will be no quotas or tariffs on goods going to or coming from the UK.
However, there will be checks on goods coming into Ireland, and Dublin Port has been transformed to deal with a new regime for examining goods and checking certificates of goods coming into Ireland.
Mr Coveney said there will be some British products that will no longer be sold in Ireland due to transport delays.
He al so said some medicines and medical products may not have EU certificates that would allow them be sold in Ireland.
Mr Coveney had in the week leading up to the Brexit deal said there was a "real risk" the deal could fall apart but said in the end "all of Ireland's core vulnerabilities" were protected.
He said the Border was protected through the Northern Ireland Protocol. Mr Coveney said the country also avoided €1.5bn tariffs on trade. However, the minister said he was disappointed on the deal around fishing rights and said he is still working on improving the agreement for Ireland.
"One area where we've been asked to take some pain, which I'm not fully happy, is the fisheries," he said.
"We are still working now on how we can ensure there is fair burden-sharing and of course how we can support the fishing sector through that disruption," he added.
He said the deal could be the "best of both worlds" for Northern Ireland despite the DUP voting against the trade agreement in Westminster.
Mr Coveney said the DUP supported Brexit yet opposed every solution put in place to try to address the Border on the island of Ireland.
"If you're going to keep voting against things you've also got to propose alternatives, and I've never heard a credible alternative to solve the issue of the Irish Border that doesn't involve either a backstop or a protocol," he said.