Tánaiste and Minister for Foreign Affairs Simon Coveney has said the European Parliament will not ratify a Brexit deal that does not have a backstop.
Speaking on BBC's The Andrew Marr Show, Mr Coveney assured that the backstop is not "dead", and said it is part of a "balanced package".
He described the Brexit deal, which was agreed with the EU but later fell flat in the House of Commons, as a "series of compromises" and said that it was designed around British red lines.
"We have already agreed to a series of compromises here and that has resulted in what is proposed in the Withdrawal Agreement. Ireland has the same position as the European Union now, I think, when we say that the backstop as part of the Withdrawal Agreement is part of a balanced package that isn't going to change."
Mr Coveney said abandoning the backstop would mean relying on an "aspirational hope".
He said that Ireland will insist on the UK "keeping its word" on the peace process, which he described as "hugely valuable".
Asked if Ireland would support an extension of Article 50, Mr Coveney said: "Yes. Ireland won't be an obstacle to more time if that's needed."
Speaking to RTÉ News today, Mr Coveney said the EU has always believed that if the UK softens its red lines and changes its approach to the relationship it is looking for, the EU will respond in "a generous and open way".
Asked if the UK had managed to open up a divide between Ireland and its European partners on the backstop, the Tánaiste said that while there was some "loose language" over the last five or six days, the EU's position remains fixed - that that there will not be a Withdrawal Agreement agreed and ratified on the EU side without a backstop in it.
Regarding the Taoiseach's comments about soldiers at the border, Mr Coveney said Mr Varadkar had been asked what a hard border would look like and that he was making the point that "we are not going back there - deal or no deal, we will work with the UK and the EU to avoid physical border infrastructure".
But he stressed there is an onus on the UK to provide solutions. "The problems are coming from London and solutions need to come from there too," he said.
Martin criticises Govt for 'mixed messages' over border
A no-deal Brexit would be "devastating" for all concerned said Fianna Fáil leader Micheál Martin.
Speaking on RTÉ's This Week programme, Mr Martin criticised the Government for sending what he called "mixed messages" on Brexit, in particular on the issue of a hard border on the island of Ireland.
Mr Martin said that the Taoiseach comments in Davos during the week, "heightened tensions".
He said that there was "no need" for Leo Varadkar's suggestion that a no-deal Brexit could result in a return of soldiers to the border.
Mr Martin said that he has not seen any alternative to the backstop, and said that the responsibility now lies with the British government to explain how it would avoid a hard border in circumstances where it can not support the backstop.
Meanwhile, Sinn Féin President Mary Lou McDonald has once again asked the Government "to call a forum on Irish unity" and to "let's start planning".
She said she believes the Taoiseach's comments in Davos on a possible hard border were unhelpful.
"Don't be reckless with your worse-case scenario of soldiers at checkpoints" she said referring to Leo Varadkar's interview in Switzerland last week.
The DUP deputy leader Nigel Dodds said the Taoiseach should take steps to quell border fears.
"It is incredibly disappointing, at this critical time, that the Irish foreign minister and the Irish prime minister use incendiary language.
"Leo Varadkar knows fine well that talk of troops being back on the border is provocative."
He accused Mr Varadkar of being "irresponsible" and called for the Fine Gael leader to clarify his comments.
"Such amateur dramatics do nothing to make progress and only play on people's fears. It's complete and utter nonsense," Mr Dodds added.
Additional reporting: Jennie O'Sullivan