The organisers of the US Open tennis championships are believed to be unhappy with the decision to postpone this year's French Open to late September. 

The rescheduling of Roland Garros to September 20 means it is now set to begin just a week after action concludes at Flushing Meadows.

The spread of the coronavirus has led to the suspension of both the men's ATP and women's WTA tours for at least six weeks.

It means there will be no play at the elite level - at the very earliest - until late April.

Wimbledon organisers say they're still aiming to begin their Championships on schedule on June 29, but will continue to "monitor and respond to the coronavirus situation on an active basis" in consultation with the UK government and health authorities.

The AELTC is continuing to monitor and respond to the coronavirus situation, working closely with the government and relevant health authorities.

While we continue to plan for The Championships at this time, it remains a continuously evolving situation.https://t.co/Tc4fSuPs9Z

— Wimbledon (@Wimbledon) March 17, 2020

But it's the moving of one Grand Slam to take place directly after another - switching from hard court to clay - could impact the participation in either or both.

It's believe the US Tennis Association was blindsided by the move of Roland Garros officials.

The USTA are believed to still be toying with the idea of changing their dates, however a statement on their site suggests battle lines have been drawn between New York and Paris.

They wrote:

The USTA is continuing to plan for the 2020 US Open and is not at this time implementing any changes to the schedule.

These are unprecedented times, though, and we are assessing all of our options, including the possibility of moving the tournament to a later date.

At a time when the world is coming together, we recognize that such a decision should not be made unilaterally, and therefore the USTA would only do so in full consultation with the other Grand Slam tournaments, the WTA and ATP, the ITF and our partners, including the Laver Cup.