Talks aimed at restoring powersharing at Stormont have reached a "sensitive" point, Irish Foreign Affairs Minister Simon Coveney has said.
Mr Coveney, who has been involved in the negotiation process along with Secretary of State James Brokenshire, said the DUP and Sinn Fein "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 told the Seanad in Dublin.
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," added Mr Coveney.
Fianna Fail 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 powersharing have so far failed, with Sinn Fein and the DUP unable to reach agreement on a number of key areas, including an Irish Language Act and legacy issues .
On Wednesday Sinn Fein 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.
But Sinn Fein chief whip Caral Ni Chuilin called for Mr Newton to resign immediately.
"His position as speaker is untenable and he needs to resign with immediate effect, given the serious concerns. The public demand integrity in government," she said.
Asked whether the allegations would impede the negotiations between Sinn Fein and the DUP over powersharing, Ms Ni Chuilin said: "I don't think anyone can ignore the serious concerns that were raised last night in the Spotlight programme.
"I don't think anybody can ignore that. We have been consistent in saying that there needs to be integrity and understanding."