The Taoiseach has said that there is a "supreme irony" in the tariff proposals put forward by the British government today.
The proposed new tariff regime is on agricultural and other products being exported from Ireland to Britain if the United Kingdom leaves the European Union without a deal.
Under a temporary and unilateral regime announced by the British government, EU goods arriving from the Republic of Ireland and remaining in Northern Ireland would not be subject to tariffs.
However, tariffs would be payable on goods moving from the EU into Britain via Northern Ireland under a schedule of rates also released this morning.
Speaking in Washington, Leo Varadkar said many of those who voted against the backstop did so because they feared Northern Ireland may be treated differently to the rest of the UK.
However, he said that what the British government is proposing "will treat Northern Ireland differently in a few weeks time, in terms of customs rules and regulations."
Mr Varadkar is in Washington DC for his annual St Patrick’s Day trip. He is due to meet US President Donald Trump at the White House tomorrow.
He said that Ireland is a "good and reliable" partner for the US, adding that Ireland is "certain about its place in the world" when others are "in chaos".
The Taoiseach also said that he is not asking America to "take sides" between the UK, EU and Ireland.
He said the US will want to negotiate a free trade deal with the UK into the future, but that Ireland will be telling the US that the Good Friday Agreement and the Peace Process has to be paramount in any deal.
He said if Mr Trump wished to appoint a special envoy to Northern Ireland, such a move would be "very welcome".
Meanwhile, the EU Agriculture Commissioner, Phil Hogan, has described the announcement on tariffs as a very ill thought out proposal, full of contradictions.
Speaking on RTÉ’s Six One, he said that it is not clear at this stage if the proposal is legal or compatible with World Trade Organisation rules.
Mr Hogan said he does not believe that the proposals will be relevant as the focus is on working to securing a deal, and not a no-deal outcome. He also said that the future trade relationship will resolve many of these issues.
Tánaiste says imposition of any tariffs would be very damaging
Earlier, Tánaiste Simon Coveney told the Dáil that the imposition of any tariffs would be very damaging and the Government would prepare a detailed response to such actions.
He said the Government will look for a further relaxation of state aid rules and EU supports for business and agri-business if there is a no-deal Brexit.
Mr Coveney was responding to Fianna Fáil leader Micheál Martin who raised concerns over the new proposed tariff regime.
"The announcement by the British government of a tariff regime has very devastating implications for Irish farming, particularly in the beef, dairy poultry and pork sector," he said.
"It would devastate the rural Irish economy, and up to €800m would be the cost to agriculture alone."
Mr Martin asked if the Government has sought any emergency aid from the EU for the agri-sector.
He said the beef sector was already in crisis and a 'no-deal' Brexit would cause "Armageddon".
Mr Coveney said the new tariff proposals would have "a negative impact on trade and will be damaging to businesses farmers and consumers in Ireland and the UK".
"We will study these proposals carefully, however, it should be stressed that no option, including zero tariffs for some product categories, or managed quotas, would be as good as what is currently on the table in the withdrawal agreement."
"The Government is in close contact with the European Commission on the issue of state aid supports.
"In February the commission announced a relaxation of state aid rules to support farmers.
"In the event of a no-deal, the Government will look for a further relaxation of state aid rules and for EU supports for businesses and agri business," he said.
"In short the crisis here, the problem here, and the uncertainty all linked to Brexit all emanate from the inability of a British parliament to be able to give a clear signal through majority support on what they will support and ratify," he said.
Mr Coveney added: "The tariffs they're proposing are being looked at in a lot of detail today, and any tariff being imposed on any agriculture product between the UK and Ireland would be very damaging and we will need to respond to that, and we will."
UK tariff proposals a 'potential disaster' - Creed
Minister for Agriculture Michael Creed said the UK's tariff proposals are a "potential disaster".
Speaking on RTÉ's Today with Sean O'Rourke, he said the bespoke arrangements for Northern Ireland outlined by the UK were complex and illogical.
He stressed that this is the scenario in the event of a no-deal Brexit and "we are not there yet".
Mr Creed said he believed the publication of the proposals was aimed at getting those who wanted to leave with no deal to see the full impact of what that would involve.
Minister for European Affairs Helen McEntee also said the proposed tariff would be disastrous for Irish farmers.
Speaking on RTÉ's Morning Ireland, she said it was now up to the British government to come forward with solutions in order to avoid a no-deal Brexit.
She said that the Irish Government had only heard of the proposals in the last few hours, but added as a member of the EU, Ireland has a duty to protect the single market.
Ms McEntee said Ireland was continuing to ramp up preparations for a no-deal Brexit.