Jacinda Ardern's pregnancy 'says a lot about the kind of country we are'

Prime Minister of New Zealand Jacinda Ardern is pregnant, and politicians are extending their congratulations.

Deputy Prime Minister Winston Peters has wished Ms Ardern "every joy". 

Mr Peters will step in as acting Prime Minister for six weeks while Ms Ardern takes leave when the baby is expected in June. 

"Ours is a novel coalition in many respects and the Prime Minister's announcement only reinforces its unique qualities," Mr Peters said in a statement. 

"We are committed to supporting the Prime Minister during the months ahead to continue to provide a good and stable government. We understand that no matter what level a person operates on, family life is important."

Congratulations also came from the Opposition.

National leader Bill English said, "Mary and I would like to extend our sincere congratulations to Prime Minister Jacinda Ardern and her partner Clarke Gayford on the news of the Prime Minister's pregnancy.

"It is an incredible privilege to be a parent. A new child will bring real joy to their lives. We wish them all the best."

Green Party leader James Shaw said the fact she can be Prime Minister and choose to have a family reflects positively on New Zealand.

"That a woman can be the Prime Minister of New Zealand and choose to have a family while in office says a lot about the kind of country we are and that we can be  modern, progressive, inclusive, and equal.

"For that reason I know this announcement will be significant for many women, in particular, and that all New Zealanders will share in the Prime Minister's joy today," said Mr Shaw.

Mr English and Mr Peters did not make media appearances on Friday. Mr Peters' spokesperson said that's because "it's the PM's day."