Britain's Northern Ireland minister must decide whether to call another election, return to direct British rule of the province or give parties more time after talks to form a new regional government failed.
Northern Ireland's parties had until Monday at 1500 GMT to form a new power-sharing government but all said a deal would not be reached after making little progress on a range of issues deeply dividing the two main nationalist and unionist parties.
The failure to restore the province's administration after its collapse in January prolongs a period of political paralysis just as Britain starts talks to leave the European Union that will determine Northern Ireland's political and economic future.
"We regret very much that there wasn't sufficient progress made but I think we will return to these issues whenever we get the space to do so," Conor Murphy, a senior member of Northern Ireland's largest nationalist party, Sinn Fein, told BBC Radio.
Murphy said Britain's Northern Ireland Minister James Brokenshire told the parties he would make a statement in the British parliament on Tuesday. A spokeswoman for Brokenshire had no immediate comment on the timeline.
By law, Brokenshire must go the polls again in "a reasonable time" once the three weeks of post-election talks elapse.
Analysts think he could announce fresh elections — the third in a year — but not set a date in a bid to provide extra time.
Both the British and Irish governments have repeatedly said they are against decision-making being taken back to London for the first time since 2007.
Sinn Fein effectively ended the talks on Sunday when they said agreement could not be reached in disputed issues including funding services for Irish language speakers, gay rights and inquiries into deaths during Northern Ireland's three decades of sectarian violence.
The two largest parties blamed each other for the collapse.
The Democratic Unionist Party's (DUP) deputy leader Nigel Dodds said his pro-British party believed Sinn Fein were never serious about getting the executive up and running and "played for time."
Sinn Fein surged to within one seat of the DUP at the March 2 election to deny pro-British unionist politicians a majority in the regional assembly for the first time since Ireland was partitioned in 1921.
The election success has emboldened Sinn Fein in increasing calls for its ultimate goal — a referendum to leave the United Kingdom and unite the island of Ireland.
"This was the worst talks process I have ever been engaged in, we didn't even have a round table discussion. It just makes you wonder what the overall tactic of Sinn Fein is," said Tom Elliott of the smaller Ulster Unionist Party (UUP).
