TAOISEACH Leo Varadkar has warned that gaps still remain between the EU and the UK over Brexit.
He said while there has been progress in the Brexit negotiations "nothing is agreed until everything is agreed".
Mr Varadkar was speaking following a meeting with Germany's Chancellor Angela Merkel in Berlin on Tuesday.
This was his first visit to the German capital as the Republic's premier.
"I think we are seeing steady progress in the Brexit negotiations, but more needs to be done in the coming weeks and months to close the remaining gaps between the EU and the UK," Mr Varadkar said.
"I thank the chancellor and German government for their ongoing and resolute support.
"We will continue to support the EU chief negotiator Michel Barnier for his critical work.
"We should all remember, we are proceeding on the basis that nothing is agreed until everything is agreed and will be working closely with partners to make sure this is faithfully respected."
Mrs Merkel described relations between Ireland and Germany as "excellent".
She said Germany fully supported Ireland's position on the Irish border issue.
Meanwhile Tanaiste and foreign minister Simon Coveney has warned the UK there will be no Brexit withdrawal treaty if there is any U-Turn on the "backstop" solution to avoid a hard border on the island.
Mr Coveney insisted the UK government has provided a "cast-iron guarantee" that will ensure no physical infrastructure, checks, or controls at the border between Northern Ireland and the Republic post-Brexit.
"Without that backstop agreement in place in the withdrawal treaty there will be no withdrawal treaty and there will be no transitional arrangements which are part of the withdrawal treaty," Mr Coveney said.
The draft text of a Brexit treaty includes an agreement between the EU and the UK that there must be a backstop solution to ensure that there is no hard border on the island of Ireland.
On Monday the UK and EU agreed terms for a Brexit transition period.
Negotiators Michel Barnier and David Davis said the deal was a "decisive step" in the Brexit process.
Speaking during Leaders' Questions in the Dail on Tuesday Mr Coveney hit back at claims that the government had failed to make any progress on the border issue.
Fianna Fáil TD Stephen Donnelly said he believed that what was agreed on Monday was a "political fudge".
He also said it was an attempt to "kick the (border issue) can down the road".
However, Mr Coveney said: "Now what we have is an agreement from the British negotiating team to put that backstop in the withdrawal agreement first so that we know there is a floor below which we cannot fall."
"And they have also agreed, as a matter of urgency, they would engage in negotiation to put a legally operational backstop in place in the withdrawal agreement and that negotiation would start as soon as next week.
"I think you should inform yourself in terms of what is progress and what's not," he told Mr Donnelly.
