Europe's Six Nations bosses and southern hemisphere rugby chiefs say they are working closely to draw up an "aligned global calendar" for when the sport resumes.

The two organisations are responsible for the major annual international tournaments, with Sanzaar (South Africa, New Zealand, Australia and Argentina Rugby) overseeing the Rugby Championship.

Coming up with a harmonised schedule of fixtures to align the northern and southern hemisphere calendars as well as ensuring fewer clashes with club fixtures has long proved a tricky task.

A joint Sanzaar and Six Nations statement issued on Friday said the two organisations had been "working closely over the lockdown period".

"Even though there may be different preferences, from the outset the nations have adopted a mindset that has sought to eliminate self-interest and recognise that the international and club game have shared mutual benefits," it said.

Although short on specifics, the statement outlined several principles that were guiding the talks.

These included "significantly" mitigating overlaps between club and country fixtures, better-aligned player-release windows and improved player welfare.

With this year's Six Nations still to be completed and the whole July programme of international matches in the southern hemisphere postponed due to the coronavirus pandemic, the sport faces the prospect of a Test match fixture pile-up later this year.

But any internationals that take place outside the designated November window could face opposition from England's Premiership and France's Top 14 as they would cut across those competitions.

The two leagues recently wrote a joint letter to World Rugby urging they be consulted on any new-look fixture list.

European Professional Club Rugby (EPCR), which runs the European Champions Cup club competition, has made it clear that it intends to stage its delayed showpiece final in October.

Sanzaar and the Six Nations said they had sought to take on board the interests of the international and club game.

"A further consultation process, in total transparency with unions, clubs and players, will commence as all parties work towards an aligned global calendar that can deliver a clear and coherent narrative," their statement said.

The coronavirus-enforced suspension of rugby union has left leading countries, heavily reliant on income from international fixtures, facing major losses.

Although other sports are returning to training, rugby faces a particular challenge as it is a full-contact sport.

On Thursday, the English Premiership announced clubs would not be back training for at least two more weeks, meaning some of the remaining nine rounds of matches may have to be scrapped in order to finish the season.