If signed off, the competition will involve 12 teams made up of the four Rugby Championship teams, along with Japan and the United States, and the Six Nations teams in a round-robin competition, but it wouldn't include any Pacific nations.
New Zealand Rugby (NZR) boss Steve Tew said the latest proposal isn't acceptable to NZR and the plan has been heavily criticised by the International Rugby Players Council, including All Blacks skipper Kieran Read.
Joseph said they simply don't have the structures in place or the resources to be involved at this point.
"It goes back to the previous questions about how do we prepare to face the top sides like the All Blacks.
"What competition structures? What High performance systems do we have to have in place to be able to play those sorts of teams. Under the current status quo it would be very difficult."
Joseph said a World League type concept would be beneficial to Japanese rugby and would help grow the game in Japan and Asia, but he hasn't seen any of the proposal in detail, other than reading media reports.
He concedes there's plenty of work to be done in Japan before his side is ready to compete in something as big as the World League, but he believes they could be involved in the future, if changes are made in the land of the rising sun.
He said more Japanese players need to be exposed to Super Rugby and at a younger age, if they're to be able to make their mark in a competition such as the World League.
"It will be tough but if we can improve the Sunwolves and get that team sorted out properly and (Japanese) players can all play Super Rugby year in year out, then yeah, in the future, why not."
That would involve a monumental shift in the current set-up and structure of Japanese rugby, something that won't happen anytime soon, with the conservative Japan Rugby Union resistant to change a system that's been in place for more than 100 years.