"Think how much stronger Tonga would have been had Charles Piutau been in this side, Samoa also with the likes of Steven Luatua... It would have made a huge, huge difference."
Impey said rich European clubs were adding to the problem.
"There have been a lot of incidents where Pasifika players, who have got their family responibilities, have made themselves curiously unavailable for their national teams because of the pressure put on them by clubs in Europe.
"I believe that you cannot put any blame on that on the Pasifika players themselves because they've got to feed their families, but it just shows World Rugby has been really poor in addressing these issues.
"New Zealand has tried a lot to make the changes at World Rugby level, but we have been blocked by being unable to get the necessary votes.
And how ironic it is that ... Scotland got dealt to by Japan with a team, from Scotland, that includes players like [Blade] Thomson and [Sean] Maitland, who learned all their rugby here in New Zealand. So the irony of it is there for all of us to see."
Impey said World Rugby could and should make the changes needed to help tier two nations. He believed the organisation also had the power to enforce the rules against European clubs.
Pacific nations are out of the World Cup tournament leaving Japan as the only tier two nation to get to the quarter finals.
This story was orginally published on rnz.co.nz and was reproduced here with permission.
