Rugby Australia (RA) have given New Zealand a three-week deadline to agree to a trans-Tasman competition in 2021 that will include five Australian teams or face organising their own domestic tournament next year.
RA interim chief executive Rob Clarke said the governing body were submitting tender documents to broadcasters on Monday for rugby rights and needed New Zealand to agree on 2021 before the broadcasters respond on 4 September.
"We can't wait much longer on the whole trans-Tasman competition decision," Clarke told reporters on Monday.
"We have a put deadline for broadcast submissions for 4 September ... So D-day is coming."
Australia and New Zealand are staging their own domestic tournaments involving their Super Rugby teams after the broader southern hemisphere competition was abandoned because of the novel coronavirus.
However, the neighbouring nations have been at loggerheads over the format of a joint 2021 competition.
New Zealand have proposed an eight to 10-team tournament featuring their five Super Rugby sides and hope to include a team from the Pacific islands.
Australia, whose four Super Rugby teams are playing with Perth-based Western Force in the domestic "Super Rugby AU" tournament, are adamant they want five teams included next year despite worries about their depth.
Clarke said Australia would be comfortable selling its own domestic competition to broadcasters in 2021 if New Zealand were unwilling to accommodate five teams.
"We've been very consistent on that," he said.
"We've been increasingly buoyed by the quality of the (Super Rugby AU) competition.
"We've been saying this to NZ ... that we're very confident in the quality of our up-and-coming talent."
Clarke said RA were also pushing for a "Super 8" competition in 2021 which would involve two teams from each of Australia, New Zealand and South Africa, as well as one each from South America and Japan.
He said that RA were offering new content to broadcasters, including a "state of union" fixture between traditional rivals Queensland and New South Wales along with domestic and international matches.