Talks aimed at restoring power-sharing at Stormont have reached a "sensitive" point, Minister for Foreign Affairs Simon Coveney has said.
"This week is an important week in the context of Northern Ireland and I hope we will have a successful outcome by the end of the week," he told the Seanad.
Mr Coveney, who has been involved in the negotiation process along with Northern Secretary James Brokenshire, said the DUP and Sinn Féin "want to make the process work" but that they still face "real challenges."
"There are sensitive discussions happening today. I am somewhat cautious in what I am saying. I don't think it would be helpful to make a running commentary today," Mr Coveney said.
He warned that a "critical phase" for the devolved institutions have been reached.
"Ten months have now passed. It means the people of Northern Ireland are not being served by an elected and accountable devolved government.
This is not a sustainable position for much longer. This is a most critical point for the devolved institutions and peace process as a whole
Fianna Fáil Senator Mark Daly warned that Northern Ireland has been "further polarised" by Brexit.
"The Good Friday Agreement has been held hostage. Unfortunately the future for Northern Ireland is neither clear nor bright," he said.
The Stormont government collapsed in January following the resignation of the late Martin McGuinness as deputy First Minister in a row over the DUP's handling of a botched renewable heat energy scheme.
Months of talks aimed at restoring power-sharing have so far failed, with Sinn Féin and the DUP unable to reach agreement on a number of key areas, including an Irish Language Act and legacy issues.
Sinn Féin has also raised concern over allegations made in a BBC Spotlight programme about Stormont speaker, DUP MLA Robin Newton.
The investigation revealed that Mr Newton has had a role with a UDA-linked community organisation - Charter NI - that he has not declared.
Mr Newton has rejected claims he misled the Northern Ireland Assembly about the true nature of his role with the organisation.