The 28-year-old back rower, widely regarded currently as the best player in either rugby code, was a World Cup winner with the All Blacks before making his return to league this year with the Sydney Roosters.
Williams has yet to announce his plans for 2014 as he contemplates another stint in the 15-man game and the next stage of his boxing career, but he is a prime target for Kiwis head coach Stephen Kearney, whose side will be defending their World Cup trophy in the United Kingdom and France in October and November, and also qualifies for Samoa.
New Zealand team manager and former Wigan winger Tony Iro, who is in England checking on hotels and training facilities ahead of the World Cup and to attend Saturday's Challenge Cup final, says the Kiwis remain hopeful of having Williams on board.
"We're in conversation with him," Iro said. "He needs to make a decision on his next career move and we're waiting on that.
"We're obviously very keen to have him available and we've talked to him a lot.
"He would be fantastic, not only for New Zealand but for the World Cup.
"He's been in great form this year. He's had a massive influence on the Sydney Roosters and I'm sure he would have a similar impact on the Kiwis."
Iro, who won 25 caps for the Kiwis and played in the 1995 World Cup in England, is less optimistic over the prospects of former captain Benji Marshall appearing in this year's tournament.
The Wests Tigers stand-off, who was removed as Kiwis skipper earlier this year, is in wretched form for his club and will switch codes at the end of the year with Auckland Blues.
"He's still in our thoughts but I think it's unlikely he'll be available given that he's signed a rugby union deal," Iro said.
"His new employers by all accounts are not that keen on him travelling and the other consideration is that he's not been in great form and, by his own admission, is behind some of the other guys in his position."
Experienced duo Kieran Foran and Shaun Johnson are expected to be New Zealand's first-choice half-backs while the availability of Williams would provide Kearney's men with a tremendous boost as they look to once more topple favourites Australia.
"We're under no illusions about how tough it will be to defend the trophy," Iro said.
"I've not been sent here by Stephen Kearney to talk down our chances but Australia have been the benchmark for a long time.
"We happened to get a couple of tournaments off them but they are the team to beat, although I'm sure England as well as ourselves will make it tough for them."
Meanwhile, Iro is tipping his old club to extend their record to 19 wins when they meet Hull at Wembley on Saturday in a repeat of the famous 1985 final which Wigan won 28-24.
"I'm really looking forward to it," said Iro, who was in the Wigan side alongside brother Kevin when they won at Wembley in 1988 and 1989.
"I wasn't there in 1985 but it was certainly one of the games that spurred me on to become a professional league player - there were a half a dozen Kiwis playing that day.
"I was lucky enough to play there twice at the old Wembley and they were probably the highlights of my career.
"I expect Wigan to win on Saturday. I know they had a soft semi-final and they've probably had a couple of results recently which weren't up to their high standards, but on an occasion like this, I think they will win, although I reckon it will be close."
- Sports & Recreation
- Stephen Kearney
- Sydney Roosters
- Tony Iro