Jacinda Ardern and Winston Peters are today expected to appear together for the first time since the new Government was announced, with the coalition agreement between Labour and New Zealand First scheduled to be signed.
In a separate ceremony, Ardern and Green Party leader James Shaw are scheduled to sign a confidence and supply agreement between Labour and the Greens.
The agreements will set out the portfolios the coalition and support partners will be given, and the policy details of the agreements.
The portfolios for New Zealand First are expected to include Foreign Affairs for Peters, a position he held from 2005 to 2008 - though the formal confirmation of the Foreign Minister will not be made until tomorrow, when Cabinet and ministerial positions are announced.
Peters is expected to be confirmed as Deputy Prime Minister today.
The Greens' portfolios are expected to include Climate Change for Shaw and Conservation for Eugenie Sage.
Meanwhile, the National Party will canvas its party leadership in a caucus meeting this afternoon.
Bill English is expected to be strongly endorsed to stay on as leader.
Deputy leader Paula Bennett is also expected to keep her post, and senior MP Steven Joyce has said he also wants to stay to hold the new Government to account.