"We consider Wayne to be an incredible asset to New Zealand rugby, not just the All Blacks but New Zealand rugby full stop," said Tew.
"He has worked incredibly hard on behalf of this organisation for an extended period of time so he has earned our respect to make whatever decision he wants to make and we are certainly not going to leave him without options, but we are desperately keen to keep him in New Zealand.
"He is one of our intellectual properties. He has been with us for so long and been such an important contributor to developing things that work in our environment that we think he is a special case to protect."
Smith helped the All Blacks clinch the World Cup trophy last year during an eight-year stint as Graham Henry's assistant.