He made his senior international debut during a friendly against Australia in 2025.
Portsmouth head coach John Mousinho highlighted the teenager's versatile skill set following the announcement of the deal.
"He's a quick, direct and aggressive winger, who is comfortable on both sides of the pitch and has a lot of experience of senior football for his age," said Mousinho.
Mousinho expressed strong confidence in the new arrival's long-term trajectory in England.
"I'm looking forward to see him continue his impressive development here at Fratton Park over the next few years," added Mousinho.
Mixed Emotions from Wellington Phoenix
Wellington Phoenix head coach Chris Greenacre voiced mixed emotions regarding the departure of the young international talent.
"I'm disappointed because I want to work with the best players and Luke's one of the best prospects in New Zealand," said Greenacre.
Greenacre indicated that the New Zealand outfit had hoped to keep the attacker long-term before the English club made their approach.
"I think we could have built a team around him," said Greenacre.
The Phoenix manager pointed to recent performances as evidence of the forward's capabilities at the senior level.
"Luke showed, particularly in the last game of the season against Macarthur, what he can produce in the A-League," said Greenacre.
Greenacre acknowledged that the move aligned with the reality of player development pathways in New Zealand.
"As a result we were keen to extend his contract, but I can understand how a move to England is difficult to resist for a young player," said Greenacre.
