British Prime Minister Theresa May has been urged to tell the Republic what her government's proposals are to solve the border issue after Brexit.
Dublin's European affairs minister Helen McEntee said the number of proposals being taken off the table seemed to make finding a solution "more and more difficult".
Her comments come after the British government ruled out remaining in any form of customs union, instead pursuing a customs partnership or arrangement in an attempt to maintain frictionless trade.
Ms McEntee told BBC Radio 4's Today programme: "It seems more and more difficult the more proposals or options you take off the table. However, we are yet to see any proposals in its absence.
"So we need the UK government, we need Theresa May and her team, to start looking at and to start I suppose letting us know what the proposals are coming from their side and what their options are.
"They have always been very clear and before the agreements in Christmas or on December 15 they made it very clear that they felt they would not need this backstop position or this backslide, that they would be able to work with the EU to create this close relationship."
She added: "So what we need to see now is how is that going to happen.
"On our part we feel that a lot of the ways of doing that have been taken off the cards - there are a lot of red line issues - so we need to see what is possible and how that's actually going to work, and to date we haven't seen that."
