Prime Minister of New Zealand Jacinda Ardern is expecting her first child in June.

Ms Ardern says partner Clarke Gayford will stay home as the primary caregiver.

"We're both really happy. We wanted a family, but weren't sure it would happen for us, which has made this news unexpected but exciting.

"Yesterday, I met with Deputy Prime Minister Winston Peters to share the news and to ask him to take on the role of Acting Prime Minister for a period of six weeks, after our baby is born."

