The initial proposal is understood to have been sent to the Six Nations and Sanzaar unions last week, with a seven-day deadline to engage in negotiations.
When asked by the Herald for comment, New Zealand Rugby said it is “not in a position to comment further”.
Along the same lines, Sanzaar said “we do not comment on commercial matters, or engage with speculation”.
The Nations Championship will have 12 teams from both the Northern and Southern hemispheres face off in a league-style competition, taking place between Rugby World Cup cycles.
Fixtures will be used to give context to test matches played in the Southern Hemisphere’s July window, and the corresponding November period for the Northern Hemisphere.
Each nation would host three matches in its own window, before touring the rival hemisphere for three away matches in the opposite.
The 12 teams will be split into two conferences of six, with the two leaders at the end of the November window to meet in a final to decide a champion.
New Zealand, Australia, South Africa and Argentina will represent the Southern Hemisphere, while England, Ireland, France, Wales, Scotland and Italy are confirmed to be playing on behalf of the north.
Two more nations, believed to be Japan and Fiji, will be invited into the inaugural competition, and take the Southern Hemisphere’s conference total to six.
However, while the competition has on one hand been welcome due to the context of matches outside of a Rugby Championship, Six Nations or World Cup, it has also come under fire for further establishing the idea of an elite group.
Limiting the total to only 12 teams will probably mean up-and-coming sides like Samoa, Tonga, USA, Canada, Georgia and Romania among others limited in their opportunities to face top-tier opposition outside World Cup years.