The country may be kept in the dark over who will lead the next government right through until next week.
New Zealand First leader Winston Peters had set a deadline of Thursday for a decision, but last night revealed it would not be made public that same day.
"Not on Thursday night, no."
He still hoped to complete all discussions by then, but could not say whether an announcement would be made before or after the weekend.
"We've got a few logistical things to sort out, but as soon as possible after that."
Mr Peters made the revelation on Tuesday evening after repeatedly dodging questions about the timeframe earlier in the day and week.
Asked if a decision was likely on Friday, he told reporters, "I didn't say that".
The timeline also depended on the other parties involved in the negotiations, he said.
"I can't answer for them."
He would not say whether the party's board would convene on Thursday night.
"We're not worrying about that at this point of time. We have to get further down the road of prioritising these talks."
NZ First was expected to meet with National and Labour at least twice each today as all parties entered the fourth day of official negotiations.
Labour and the Green Party were also set to meet this morning.
NZ First's board was on standby for when the caucus reached a decision.
Mr Peters posted on his public Facebook page on Tuesday in bid to assure the public that the party was working towards a decision "as fast as we can".
He said whatever choice the party made would cause "disappointment and anguish".
"That's reality and there is no escaping that," he said.
However, the decision over the next government would be made in the "greater interests of this country and its future," the post said.
"We want the best for our country."
Earlier on Tuesday, Mr Peters told reporters there was a "fair way to go yet" in terms of how much policy still had to be discussed.
"We're seriously working on the various policies that other parties have got that may be relevant or not relevant to our final decision.
"But whatever that decision is, we know we're going to disappoint people. It's just a statement of fact."
Delay shouldn't surprise NZ - ACT leader
ACT Party leader David Seymour told Morning Report politicians traditionally waited until they were in government before they started to break their promises.
"But Winston Peters has brought a new innovation by breaking his promise to decide tomorrow, before a government's even formed.
"And sadly for New Zealand, this shouldn't be a surprise."
He said the real reason for the delay was that Mr Peters was negotiating for himself to become Prime Minister.
"That is the one big prize that Winston Peters really wants," Mr Seymour said.