Taoiseach Leo Varadkar has said "the gap is very wide" between the EU and the UK in reaching a deal on Brexit.
Speaking on RTÉ's Morning Ireland from the Fine Gael party think-in, Mr Varadkar said that while the Irish Government has always been willing to explore alternative arrangements, "what they are seeing falls very far short" of what is needed.
He said "we are exploring what is possible", adding "the gap is very wide but we will fight for and work for" a deal until the last moment, but "not at any cost".
Mr Varadkar also said he believes British Prime Minister Boris Johnson "is acting in good faith" when he says he wants a deal on Brexit.
The Taoiseach said that while some customs checks could be required close to the border in the event of a no-deal Brexit, the Government has not yet identified any location for where those checks would take place.
The Taoiseach said Fine Gael "would have to be willing to enter into a Confidence and Supply Agreement" with Fianna Fáil, if Micheál Martin's party emerges as the largest after the next general election.
Mr Varadkar said yesterday that May 2020 was the "right moment" for a general election.
When asked would he support Fianna Fáil if the party becomes the biggest after the next election, Mr Varadkar said: "We would then have to negotiate a confidence and supply agreement.
"If the shoe is on the other foot, if they were the largest party and we were the second party, we would have to give consideration in that circumstance.
"We would obviously expect in that agreement a lot of our policies to be reflected."
The Taoiseach also hit out at Fianna Fáil in the interview, accusing the party of "going around the country promising everything to everyone" and he said "their promises can't be believed".
He said that while Fianna Fail had not voted the government down or collapsed the government, it "doesn't give them a free pass on the kind of false promises that they are making or the reckless spending commitments that they are committing to".
Mr Varadkar was also questioned on the comments reportedly made by Independent Galway TD Noel Grealish at a public meeting in Oughterard on the plans to open a direct provision centre.
Mr Grealish reportedly said the people who might possibly be housed in a former hotel would be African economic migrants, whom he described as "spongers".
The Taoiseach said he did not hear the alleged comments, but he said: "If that is what he said, I think he should withdraw those remarks. At the very least make a statement on them and clarify them."