"It is France's role to make every effort to ensure that all parties agree to a break and open negotiations," the French presidency said.

The 2015 deal over Iran's nuclear programme has begun to unravel since US President Donald Trump announced Washington was pulling out of the agreement last year and reimposed sanctions, to the dismay of European allies.

France, Britain and Germany were among the key players in the pact.

Macron had a "long" discussion with Rouhani during the French leader's annual holiday at his summer retreat, the medieval fort of Bregancon on France's Mediterranean coast, the Elysee said.

Macron "recalled the need to initiate a de-escalation of tensions," it added.

Paris has engaged in intense diplomacy seeking to solve the current tensions, with Macron's foreign policy advisor Emmanuel Bonne twice visiting Tehran.

Russian President Vladimir Putin is due to visit Macron in Bregancon in mid-August ahead of a G7 summit in Biarritz which will present "new opportunities to discuss the Iranian issue", according to the Elysee.