The new format is intended to increase competitiveness by creating a Six Nations or Rugby Championship-like tournament for tier-two countries ahead of the 2027 World Cup, which has been expanded to 24 teams from 20.
The United States, Canada, Fiji, Japan, Samoa and Tonga were confirmed as the six teams for the 2024 edition of the Pacific Nations Cup. They will be split into two pools of three teams each, the governing body said.
The final series of this year's competition will be held in Japan, with the U.S. hosting the final in alternate years.
Each team will play at least three matches, with Fiji, Samoa and Tonga making up Pool A, and the top two teams from each pool advancing to the semi-finals.
The teams in each pool play each other in home or away fixtures in a round-robin format, with the pools themselves created with an eye on reducing long-distance travel and the competition's carbon emissions, World Rugby said.
"The six teams taking part in the competition will benefit from long-term certainty around fixtures, allowing them to optimise their preparations and engage with fans and commercial partners," World Rugby's High-Performance Pathways and Player Development Manager Simon Raiwalui said.
"With so much talent in the Pacific Islands, Japan and the two North American teams, fans can expect a tough contest and a great spectacle epitomised with epic finals in Japan."
The fifth-place playoff and semi-finals will be held in Tokyo, with the 2024 final taking place in Osaka.
"The model... provides unprecedented certainty of fixtures for unions... while the grand final in the USA every two years is at the heart of our strategy to grow rugby visibility," World Rugby CEO Alan Gilpin said.
