Ardern, 42, said on Thursday she had "no more in the tank" to continue leading the country and would step down no later than early February and not seek re-election.

Labour Party lawmakers are due to vote for a new leader on Sunday. If a candidate is unable to secure two thirds of the available votes, the leadership contest will go to the wider membership.

The winner will become prime minister until the next general election. Ardern's term as leader will conclude no later than Feb. 7 and a general election will be held on Oct. 14.

Commentators point to a number of Ardern's ministers as possible candidates for the role, including the former COVID minister and current Minister of Education and Police Chris Hipkins and current Minister of Justice Kiri Allen.

(Reporting by Lucy Craymer; Writing by Alasdair Pal; Editing by Sandra Maler)

By Lucy Craymer