Taoiseach Leo Varadkar has said that the latest Brexit proposals from the British government do not fully meet the agreed objectives of the backstop.
He made the comments in a statement following a phone call with British Prime Minister Boris Johnson. The two leaders spoke shortly before 6pm this evening.
A spokesperson for the Government told RTÉ News that the conversation was "constructive, useful", but there was "more work to be done".
In the statement, Mr Varadkar indicated that he would study the proposals in further detail, and would consult with the EU institutions, including the EU task force and our Ireland's European partners.
The Taoiseach is due to to speak with European Council President Donald Tusk, European Commission President Jean-Claude Juncker, and with other EU heads of government over the coming days.
He will be in Sweden and Denmark in the coming days to speak to his counterparts there.
Mr Varadkar said he wants to see a deal agreed and ratified, and would continue to "work in unity with our EU partners to this end".
The Taoiseach and Mr Johnson agreed they would speak again next week.
The Brexit proposals submitted to the European Union by Mr Johnson received a very cool response from Opposition parties.
Sinn Féin President Mary Lou McDonald said that the new proposals must be rejected.
In it, Mr Johnson proposed a "new protocol on Ireland/Northern Ireland" to replace the backstop that was included in the original Withdrawal Agreement.
Ms McDonald asked if he was serious at all and if he even wanted a deal on Britain leaving the European Union. She also said the plan would hand the DUP a veto.
Fianna Fáil's spokesperson on Brexit said that the possibility of a no-deal Brexit now loomed large over Ireland.
Lisa Chambers described the plans as "not realistic and fall very far short of what is required".
She added: "In my view the proposals show a complete lack of regard for Ireland and the sensitives involved."
Labour leader Brendan Howlin said it was "worrying" that Mr Johnson's proposal declared that the UK intended to break from a close alignment with the EU.
"It is hard to see how the Ireland-specific Brexit proposals could work if the UK departs from EU standards and rights," he said.
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Shortly before the new Brexit proposals were released, the Taoiseach called for Mr Johnson to deal with all the parties of Northern Ireland equally.
He urged the prime minister not to favour the DUP above the rest of the Stormont parties.
"As Prime Minister he must act with impartiality and listen to all the parties of Northern Ireland, and the people of Northern Ireland, who voted against Brexit and do not want to see customs posts on the border, " Mr Varadkar said.
"It will be necessary to have checks, but we believe they should be done at ports and airports, not along the 500km border. That's our position and makes sense to us.
"No-one on the island of Ireland wants checks at the border, why would any British government want to force that on Irish people, north and south?"
When it was put to Mr Varadkar that Mr Johnson had referred to the Irish border as a "technical issue", the Irish leader disagreed.
"It's much more than technical, it's deeply political, legal, and the technical aspects are a small part of that."
When asked if he still believes Mr Johnson wants a Brexit deal, Mr Varadkar said: "I do."
Additional reporting Paul Cunningham, PA