Asia cannot yet consider joining the proposed Super Rugby expansion because the expected costs of building and developing the 18th franchise will "bankrupt any union", Asian Rugby Football Union president and Hong Kong Rugby Union chairman Trevor Gregory says.

SANZAR recently announced plans to expand Super Rugby into an 18-team, four-conference tournament, adding a sixth South African franchise - the Southern Kings - a team from Argentina and an undetermined 18th franchise to be put up for tender.

Greg Growden reported recently in Ruck'n Maul that "SANZAR officials have been eager for some time to have a Super Rugby base in Asia" and "within SANZAR the push for a Super Rugby team in Singapore is intensifying".

But Gregory said this week that he could not "see the money being available in Asia right now".

"The whole concept of getting a franchise up for the next five years, I don't want to pour cold water on it, I really feel it's a bridge too far," Gregory told Reuters. "We have a very small budget for running the whole of Asian rugby which is less than $US2 million for 28 countries. Having to source the sponsorship for Asian rugby which I have had to do for the last six or seven years, I cannot see the money being available in Asia right now."

Singapore rugby officials have not ruled out bidding for the 18th franchise, but Gregory said Hong Kong was not interested and he doubted whether Japan wanted to become involved because the Top League was a thriving competition featuring some of the best players in the world "and for them, that is sacrosanct".

Gregory said the finances of developing a team did not add up for the Asian unions.

"Can you imagine a union having any liability for a five-year contract that could have a $US100 million price tag on it," Gregory told Reuters. "That would bankrupt any union."