Williams' manager Khoder Nasser said that his client had achieved everything he wanted in league, the Daily Telegraph reported in Sydney .
Nasser added that Williams would consider switching codes and signing with the NZRU -- and that he was likely to make a decision on his future by mid-June.
``He has made a statement and if an (NZRU) offer was to come, he would definitely consider it,'' Nasser said.
``He was basically saying he has achieved what is there to be achieved in league.
The comments were greeted with surprise by NZRU chief executive Steve Tew, who said he would be happy to talk to Williams - or his management team - but only if they were serious.
``We are not interested in being part of a contract negotiation,'' Tew said.
The Kiwi second-rower is in the first year of a five-season $A2 million ($NZ2.4 million) contract with the Bulldogs but admitted he wasn't happy and was weighing up his future.
Nasser said he will talk with Williams next week.
``These things are all going to come to a head soon,'' he said. ``We will have to work out what will happen, we are going to have to meet up with the club (the Bulldogs) in the next two to three weeks.''
Former Australia coach Eddie Jones said Williams could earn up to $800,000 a year if he headed to Europe.
But the Bulldogs have warned they would consider legal action if Williams attempted to break his contract with the club.
