Winston Peters says he's still to sit down with the New Zealand First caucus and board to make a final decision on who'll form the next Government.
He also hasn't decided whether to inform National leader Bill English and Labour's Jacinda Ardern before making the decision public, which he expects will happen Thursday afternoon.
"The reality is we have to make up our mind about that, and we've set our target... I don't see any reason we can't achieve that," he told Newstalk ZB on Thursday morning.
"We're going to finish off the work we're currently engaged in... we'll spend some considerable time going through that as a caucus... We'll be coming to a decision and making an announcement sometime in the afternoon."
He expects to make the announcement himself, rather than giving the future Prime Minister the opportunity.
It's been almost a month since the election, but Mr Peters says the discussions have been "way shorter" than those held overseas, such as in Germany where they're not expected to be completed until next year.
"It's exhausting for all the teams, because unlike most political meetings you've got to pay attention from the start to the finish."
He said criticism that NZ First, which only has nine seats, holds all the power is "illogical".
"The fact is whatever we decision we make will make a majority in Parliament."
He said MMP is much fairer than the old first-past-the-post system, under which "sometimes 35 percent could make the decision".