The new head of New Zealand's ruling Labour Party, Chris Hipkins, has officially taken office as the country's prime minister, replacing Jacinda Ardern.

Hipkins was sworn in on Wednesday in the capital Wellington in front of the country's Governor-General Cindy Kiro.

Hipkins was first elected to parliament in 2008. Under Ardern, he served as education minister and in other posts including COVID response minister.

Carmel Sepuloni was also sworn in as deputy prime minister. She is the first person with Pacific Island heritage to assume the post. Her father is from Samoa. The appointment reflected Hipkins' stance of placing importance on diversity.

Speaking at a news conference, Hipkins stressed that he will primarily focus on pressures of the cost of living faced by the public. Dissatisfaction is rising over recent inflation.

He will be looking to restore voters' support before a general election scheduled for October.

Ardern, who announced that she is stepping down from her job last week, gathered global attention by taking maternity leave as the world's first elected leader and for her handling of the coronavirus pandemic.

She made her final official appearance as prime minister on Tuesday, attending a gathering of politicians and Maori elders. Looking back on her term in office, Ardern said her experience in the job has been one of love, empathy and kindness by the majority of New Zealanders.