Helen Clark reacts to Jacinda Ardern as PM

Former New Zealand Prime Minister Helen Clark has shared her praises for Jacinda Ardern following the announcement that Labour will lead the next Government.

Clark wrote on social media: "Congratulations Jacinda Ardern - about to become New Zealand NZ Prime Minister after an extraordinary election campaign and successful negotiations to form a new government.

Helen Clark has praised Jacinda Ardern on Twitter. Photo / Getty

"I wish Jacinda, the NZ Labour Party, NZ First, and the Green Party every success in their work to build a better, fairer, more sustainable, and successful New Zealand."

Clark said it was a historic moment, with Ardern set to be New Zealand's third female Prime Minister.

Congratulations #JacindaArdern on becoming #NZ 🇳🇿 Prime Minister & being 3rd #woman to be NZ PM. Historic times. 🌹🌹 https://t.co/46p3dlahri

— Helen Clark (@HelenClarkNZ) October 19, 2017

Ardern's Labour Party was chosen by NZ First leader Winston Peters over National after almost two weeks of negotiations.

It will give NZ First four ministerial posts in Cabinet and an under-secretary post. Peters has been offered Deputy Prime Minister, but is yet to decide whether to take it.

The Greens will not be part of the formal coalition, but will provide confidence and supply and get three ministerial posts outside Cabinet.

Ardern said she was "overwhelmingly humbled" to learn she would be Prime Minister.