Mr Macron spoke to Iranian President Hassan Rouhani for an hour on Saturday – just a day before Iran is set to announce an increase in uranium enrichment purity above the limit laid out in the deal with other world powers.
A statement from Mr Macron’s office said: “The president recalled his deep concern in the face of the risk of a new weakening of the 2015 nuclear accord, and the consequences that would necessarily follow.”
The French president also said would “explore between now and July 15 conditions for resumed dialogue among all parties.”
Mr Macron’s office did not give any further details over the new date of July 15 and what was set to happen until then.
According to Iranian state TV, Mr Rouhani told Mr Macron that “lifting all sanctions can be the beginning of a move between Iran and six major powers”.
“The US sanctions are a full-scale economic war against Iran that could create more crisis in the region and in the world,” he added.
The warning came amid tensions between Iran and the US, a year after President Donald Trump pulled out of the nuclear deal and reimposed sanctions on the gulf nation.
Iran is set to announce on Sunday that it has increased its enrichment to 5%, despite the deal limiting it to 3.67% – breaking the terms of the Iran Nuclear Accord.
The country says its nuclear programme is for purely peaceful purposes, but there are concerns that increasing its capacity could lead to the production of nuclear weapons.
The announcement early on Sunday morning is being seen as a setback for the remaining signatories of the agreement, including the UK, which is urging Iran to remain committed to the deal.
Iran is seeking a lifting of the US sanctions, which has badly hit their oil exports, as a precondition for beginning talks with the six signatory nations.