The Sanzaar nations - South Africa, New Zealand, Australia and Argentina - are in talks with the Six Nations teams.

At present, the international rugby windows differ in the northern and southern hemispheres.

A joint statement read: "The nations have sought to eliminate self-interest and recognise the international and club game have shared mutual benefits."

England, Wales, Scotland, Ireland, France and Italy are the Six Nations teams.

The statement added that a global calendar would "improve player welfare" and "improve narrative and competitiveness of international and domestic competitions around clear windows".

A harmonised schedule of fixtures - that would avoid conflicts between club and country for players' time and create more opportunities for lucrative matches between the biggest international teams - has been an ongoing issue in the sport.

A summit in San Francisco in 2017 failed to deliver large-scale change, however. Plans for a Nations Championship, to bring more fixtures and a structured format to the international game, failed to get off the ground in 2019.

Newly re-elected World Rugby chairman Sir Bill Beaumont told BBC Sport last month that he was hopeful that a revised Nations Championship could have enough support to become reality.

The outbreak has brought the game to a halt globally. While domestic rugby is set to restart in New Zealand on 13 June, the curtailed English Premiership and Pro14 are not likely to get back under way until at least August.