Jacinda Ardern 'confident' in negotiation talks - but wink was unintentional

Jacinda Ardern says she's feeling "absolutely" confident in negotiation talks with New Zealand First.

"We're still going through a process, but we have every reason to feel confident or at least as confident as the other party involved," Ms Ardern told The AM Show on Tuesday morning.

Winston Peters has surpassed his self-imposed deadline by five days, but is expected to make a decision on how the next government will be formed this week.

Ms Ardern says while talks have been smooth-sailing, a wink she gave during a Facebook video over the weekend was unintentional.

In the video, she said discussions would result in a Government she would be "proud to lead", before saying there was "a little wait" before that would happen, giving a wink.

"I've got a tick," she explained to The AM Show, "which obviously now everyone knows".

"I didn't actually even realise that I'd winked, but my father confessed to me last night that sometimes he has a tendency to do it too so I think I've got some kind of genetic issue there, which now the whole country knows about."

On Monday caretaker Prime Minister Bill English said talks with the National Party were not as advanced as people may think.

But Ms Ardern says "both parties are being treated completely even-handedly in that respect".

"Mr Peters himself has said these have been talks that have been dominated and focused almost entirely on policy.

"It should be heartening to people that in these discussions, parties have been focussed on the ideas that they want to deliver to New Zealanders, rather than simply the positions they might get out of an arrangement.

She then reinforced all parties have negotiating power - not just NZ First.

"There's been a lot of commentary around how this is something that somehow the major parties are... 'lap dogs' of the situation. I really push back on that.

"In these negotiations we have it within our power to say that these are the things that we're willing to talk about and compromise on, and these are the things that we are not."

She would not say whether she had said "no" to Mr Peters during talks, adding she was simply trying to make a point that the major parties "have a role to play in this as well".