Star prop Martin Taupau has announced his withdrawal from New Zealand's mid-year Test squad 18 hours after it was named to declare his allegiance to Samoa.

The Manly enforcer's impending move is a huge boost for the island nation, with Taupau set to join an Anthony Milford-led Toa Samoa side against Papua New Guinea at Leichhardt Oval next Saturday.

Taupau made his representative debut for Samoa in 2013 before rising to prominence as a Kiwi regular the next season and representing New Zealand 24 times since.

The 29-year-old announced the news on Twitter after telling Kiwi coach Michael Maguire of his decision on Friday morning.

"After hours of soul searching and plenty of discussion with my fiancé and family, I had to make a tough call to the NZ Kiwis coach Michael Maguire this morning to inform him that I have made the decision to make myself unavailable for selection for the NZ Kiwis, and elected to make myself available for the Toa Samoa team once again," Taupau's message read.

"I am incredibly grateful for the opportunities that were given to me and the ability to represent my birth nation.

"In 2010 I had the honour of captaining the Junior Kiwis and then made my international debut in 2014! Since then I have worn the NZ jersey with pride and passion 24 times and will forever cherish every moment."

I’ve got a very important announcement that i would like to make 😊 pic.twitter.com/nO8ms1gTvk — Martin Taupau (@MartyKapow) June 14, 2019

While he was born in Auckland and grew up in the New Zealand city and Sydney, Taupau has long taken pride in his Samoan heritage from his parents.

He travelled to Samoa for the first time in 13 years during the off-season at the invitation of the Australian High Commission to help promote the emergence of young female leaders in developing communities.

His move sees him follow a similar path to big name Tongan's Jason Taumalolo and Andrew Fifita, who put the Mate Ma'a by shifting from tier-one nations New Zealand and Australia to spearhead a remarkable 2017 World Cup run.

Samoa's squad for the Pacific Test clash will be named on Sunday night, with Milford and Taupau expected to headline a team also featuring Newcastle's James Gavet and the Warriors' Isaiah Papali'i.

Tickets are available for the Pacific Tests at Leichhardt Oval viaTicketek - Get yours now