DUP leader Peter Robinson has said the Stormont talks need to reach a conclusion by the end of next week or "there will be no agreement".
Speaking to the media for the first time this week, the first minister said the all-party negotiations were "coming to a vital stage - the endgame".
The talks process addressing paramilitary activity and the implementation of last Christmas's Stormont House Agreement that began last month was expected to intensify towards the end of this week.
However, Mr Robinson indicated that there would be another full week of negotiations involving the two governments and the assembly's five biggest parties.
But he warned that if a deal was not forthcoming by the end of the next week there would be no further talks.
"It is my view that if we can't reach agreement then the process itself will be terminated," he said.
The DUP leader said a range of issues remained outstanding.
"I don't see any of them as being insurmountable, if there is goodwill on the part of the parties," he said.
"I believe it is possible for us to get a deal, but it does require leadership, it does require commitment and it does require all of the parties to stretch themselves."
On Wednesday, Deputy First Minister Martin McGuinness said he believed a deal was "achievable", within a timeframe of "days not weeks".
Meanwhile, an opinion poll has highlighted the unpopularity of the DUP's recent policy of resigning and re-nominating its ministers.
The Lucid Talk Big60 poll, published in Thursday's Belfast Telegraph, showed that 84 per cent of respondents felt Mr Robinson made the wrong decision in withdrawing all but one of his ministers from the executive in the wake of last month's arrest of Sinn Féin northern chairman Bobby Storey.
Just over a third of DUP voters (35 per cent) approved of the move, while 54.4 per cent thought exiting the executive was a bad idea, of which more than half were "totally against it".
