"But the calendar provides new opportunities for all our members and embraces the expansion of Nines, providing an exciting future for players, supporters and members alike."
The four-year cycle also includes an Emerging Nations championship in 2018 leading up the 2021 World Cup in the UK.
The RLIF board announced that World Cup qualification will be concluded two years in advance, with the line-up for 2021 to be completed by December 2019.
The international governing body also pledged to support the development of tier-two nations, those outside the big three, by working with continental federations to strengthen existing regional competitions in Europe, Asia Pacific, the Americas and Middle East/Africa.
A dedicated mid-season international weekend will be created, giving nations an opportunity to build on the success of this year's Pacific Test series in Sydney.
The RLIF are also committed to putting together a business plan for international Nines with the potential for a World Cup for men and women in 2019 and for both youth and women's nines to become a part of the Commonwealth Games Festival in 2018.