French President Emmanuel Macron and US President Donald Trump said on Sunday that the members of the Group of Seven (G7) will each act on its own over the thorny issue of the Iranian nuclear deal.

"There is no formal mandate at G7. We will continue to act, each in his own role," Macron told reporters at the G7 summit. "G7 is an informal club. We do not give formal mandate to this one or that one."

Earlier in the day, Macron told French television LCI, "we agreed on what we wanted to say jointly on Iran". "Everyone wants to avoid a conflict, US President Donald Trump was extremely clear on that point," he said.

French media reported that Macron has obtained a mandate to deliver a message to Iran on behalf of the seven countries, following the leaders' dinner on Saturday.

"No, I haven't discussed this," said Trump, however, on Sunday morning when asked about "joint action" over Iran at a joint press conference with Japanese Prime Minister Shinzo Abe.

When asked whether he supports Macron's outreach concerning Iran, Trump said, "Sure. But I also support Abe's outreach. (...) We'll do our own outreach. You can't stop people from talking. If they want to talk, they can talk."

Iranian Foreign Minister Mohammad Javad Zarif said on Friday after his talk with Macron in Paris that France has offered proposals to Iran about ways to implement the Iranian nuclear deal, officially known as the Joint Comprehensive Plan of Action (JCPOA).

Iran and the five permanent members of the United Nations Security Council, the United States, France, Britain, Russia and China, plus Germany signed the nuclear agreement on July 14, 2015.

However, the United States pulled Washington out of the deal last year and re-imposed sanctions on Tehran, which had been lifted under the accord. In reaction, Iran also dropped parts of its obligation to the deal recently and threatened to do more.