The Board of International Rugby League has announced the updated rules, which come into effect immediately, following a review and consultation with member nations.
Under the new regulations a player is eligible to represent any nation they, their parents, or grandparents were born in, or if they have resided in the country over a five-year period.
However, changes introduced before the 2017 World Cup that were hailed as game-changing and inspired the rise of Mate Ma'a Tonga have been tightened.