Prime Minister Jacinda Ardern has gifted The Duke and Duchess of Cambridge a special New Zealand-themed romper, among other gifts.
A statement from Kensington Palace revealed Duchess Catherine delivered their third child, weighing 8lbs 7oz, at 11:01am on Monday morning.
The baby is Prince William and the Duchess of Cambridge's third child together, joining Prince George, four, and two-year-old Princess Charlotte in the royal family.
Ms Ardern has formally congratulated the royal couple.
"I am sure that New Zealanders join with me in celebrating the birth of a new baby to such a close and loving family."
New Zealand's official gift to the couple will be a hand-crafted 100 per cent wool baby blanket featuring a manuka flower and seed pod design, along with a selection of New Zealand children's books.
"I also gave a personal gift of hand-made rompers with buzzy bee lining, sewn by a family member."