PARIS (Reuters) - France suggested on Wednesday that the nuclear deal Iran struck with world powers in 2015 could be supplemented through “future consultations” to include the post-2025 period and tackle Iran’s development of ballistic missiles.

French President Emmanuel Macron addresses a speech during the annual gathering of French Ambassadors at the Elysee Palace in Paris, France, August 29, 2017. REUTERS/Yoan Valat/Pool

Under the deal, most international sanctions were lifted in return for Iran undertaking long-term curbs on its nuclear program, which the West suspected was aimed at developing the means to build an atomic bomb.

Iran agreed to mothball for at least a decade the majority of its centrifuges used to enrich uranium and sharply reduce its low-enriched uranium stockpile. It also agreed restrictions on its ballistic missile programs for eight years.

“The President (Emmanuel Macron) on Aug. 29 indicated that the Vienna accord could be supplemented by work for the post-2025 period (and) by an indispensable work on the use of ballistic missiles,” Foreign Ministry spokeswoman Agnes Romatet-Espagne told reporters at a daily briefing.

“This work could be the object of future consultations with out partners,” she said, referring to Macron’s comments.

The United States, Britain, France and Germany have complained several times to the United Nations about Iran’s tests of ballistic missiles, which they contend are “in defiance” of a 2015 U.N. resolution enshrining the nuclear deal.

Diplomats said Macron’s comments, in which he also stressed that the deal was “good”, came amid concerns in Paris that U.S. President Donald Trump could walk away from the nuclear accord, which he has called “the worst deal ever”.

Trump has ordered a review of the accord, negotiated under his predecessor Barack Obama, and allies including France fear Washington could renege on the deal in some way and risk Iranian retaliation, escalating instability in the Middle East.

“The Vienna accord on Iran’s nuclear program is essential for regional and international security and non-proliferation,” Romatet-Espagne said. “There is no credible alternative.”

She added that France, which has struck several multi-billion dollar deals in Iran since the 2015 agreement, neither wanted to reopen or renegotiate the accord, but to ensure it was being implemented rigorously.