Macron, who will visit the US later this week, made the comments on Sunday in an interview with Fox News, adding that he sees no plan B for the deal. Although admitting that the deal is not perfect, Macron said there are currently no better solutions.

The same day, German Chancellor Angela Merkel said an imperfect Iran deal is better than no deal. Trump, who has called the agreement the "worst deal in history", has said he will scrap it unless "a better option" is presented to him in May, when a deadline on renewing the deal will pass.

Iran's foreign minister made the point more dramatically, warning that if Trump quits the 2015 accord, Tehran may respond by relaunching and intensifying its now-blocked nuclear program.