The 26-year-old Highlanders star announced on social media that he’s signed a three-year deal with English club Wasps.
Sopoaga, who recently became a father for the first time, said it was a difficult decision to make.
“It’s with a heavy heart that I announce that my family and I will be leaving NZ at the end of the 2018 season,” Sopoaga wrote on Instagram.
“It was one of the hardest decisions I’ve ever had to make but is one I’m at peace with. I have loved every minute of being a professional footballer here in NZ, I’ve made life-long friends and memories that I’ll cherish forever.
“I’d like to thank the Highlanders, All Blacks, Southland and Wellington for the awesome experiences you have provided me with over the years. Thank you to all the fans for your support it’s been one heck of a ride.
“To my team-mates and coaches over the years thank you for everything, I’ve been blessed to have met so many top men. Last but not least to my family & friends you know who you are the ones who have stood by me through the lowest of lows and the highest of highs you have seen both the valleys and the peaks, THANK YOU will never be enough!
“So here’s to 2018 one last roll of the dice before I head off to experience life on the other side of the world. I’m ready.
Sopoaga has played 16 Tests for New Zealand, making his debut against the Springboks in 2015 and was a key part of the Highlanders inaugural Super Rugby title win the same year.
All Blacks Head Coach Steve Hansen said: “We’re disappointed to be losing Lima but we understand his reasons for leaving. He has been upfront and communicated with us through the process and when he leaves, he and his young family will go with our best wishes. Our job now will be to develop the next player to take his place.”
The All Blacks will now have to find a replacement first-five to back up incumbent Beauden Barrett, with Richie Mo’unga and Damian McKenzie appearing the most likely contenders.