Prime Minister Jacinda Ardern has kept her Christmas promise, wearing her bespoke Mike Hosking face mask.

In a photo posted to Instagram, Ardern can be seen wearing one of the face masks broadcaster Hosking gave her.

It is a red face mask with Hosking's face printed on the front, given to her a few weeks ago.

As Hosking headed off on his summer holiday, he caught up with the Prime Minister for their annual present swap - and in typical 2020 style, swapped gifts over Zoom.

The ZB host gave Ardern face masks with his own face printed on the front.

The face masks featured four in total the "big one", "full body Mike", "multiple heads Mike", and "really multiple heads Mike".

"Next time you are on a plane you must promise me to put one on, selfie it and get it out to the world out on social media," Hosking asked Ardern.

She told Hosking, she thought he had gifted her a 'g-string'.

"When I first opened it, I briefly worried it was a g-string," Ardern laughed.

Hosking kept the 2020 theme going with his gift, while Ardern opted for a more electoral present.

• Mike Hosking and Jacinda Ardern swap Christmas presents - 2020 style

Jacinda Ardern gave Mike Hosking a hilarious Christmas gift during their festive gift exchange. Photo / ZB

She gave Hosking a Labour billboard featuring the ZB host alongside herself, a present she says Hosking will grow to love as the years roll on.

"Her gift to me is quite clever, and I'm going to treat it appropriately and put it in the right place. It's quite cool," Hosking said on air.

"Do you want me on board? Have you seen my magnetism as a vote-getter?" Hosking joked.

"Over time I will indeed learn to love it. I'll put it straight to the pool room."

Hosking also gave Ardern's daughter Neve a Micky Mouse soft toy with Neve's name stamped on Micky's foot, wowing Ardern as she unwrapped the gift.

"The Neve gift is sensational. The Ardern gift, God bless her for being a good sport. It could have gone either way."

Mike Hosking gifted Jacinda Ardern a face mask with his face printed on the front. Photo / ZB