TEHRANinfo-icon: Iraninfo-icon's President Hassan Rouhani rejected any hopes of rewriting a nuclear deal with worldinfo-icon powers on Wednesday, after the leaders of the United Statesinfo-icon and Franceinfo-icon suggested a new pact covering Tehran's missileinfo-icon programme and regional interventions.

"We have an agreement called the JCPOA," said Rouhani in a fiery speech, using the technical name for the 2015 deal that curbed Iran's nuclear programme in exchange for sanctions relief. "It will either last or not. If the JCPOA stays, it stays in full."

He was responding to statements in Washington by French President Emmanuel Macron and his USinfo-icon counterpart Donald Trumpinfo-icon, in which they proposed a new deal with tougher restrictions on Iran.

Trump called the existing accord "insane" and "ridiculous", despite European pleas for him not to walk away, and demanded fresh curbs on Iran's ballistic missile programme and support for militant groups across the Middle Eastinfo-icon.

Macron said a new agreement should include a settlement on Syriainfo-icon, where Iran backs President Bashar al-Assad.

In Iran, Rouhani responded by ridiculing Trump, saying: "You have no expertise in politics, nor in law, nor in international accords. A trader, a businessman, a high-rise builder, how can he judge about global issues?"

Iran has the support of all other parties to the accord, who say it is working and Tehran has stuck to its commitments.

On Wednesday, EU diplomatic chief Federica Mogherini insisted the deal must be maintained. "On what can happen in the future we'll see in the future, but there is one deal existing, it's working, it needs to be preserved," the former Italian foreign minister said as she arrived for a donor conference on Syria in Brussels.

Moscowinfo-icon also reiterated its support, with Kremlin spokesman Dmitry Peskov telling reporters: "We believe that no alternative exists so far" and demanding that Iran be involved in any further discussions.

Looming decision

Macron, who has built a warm rapport with Trump, has positioned himself as an emissary for European officials seeking a compromise that allows the mercurial US president to claim a public victory, while keeping the deal intact.

The Europeans appear to be hoping they can sell Trump on the idea of broader regional settlement with Iran that would complement, rather than replace, the existing nuclear deal.

"The biggest priority is maintaining the existing nuclear accord. It was negotiated by seven countries and the EU and can't be renegotiated by one or other party," said German foreign spokesman Rainer Breul.

"President Macron ... spoke of the need for supplementary agreements. The question is whether, and in what circumstances, Iran would be ready to enter into such a process," he added.

German Chancellor Angela Merkel is expected to press the European case again when she visits Washington on Friday.

For now, Macron admitted he could still not read whether Trump would simply walk away from the existing deal when it comes up for renewal on May 12, as he has threatened.

True to his background in reality TVinfo-icon, Trump has kept everyone guessing. "This is a deal with decayed foundations," he said. "We're going to see what happens on the 12th."

Iran has warned it will ramp up enrichment if Trump scraps the accord, prompting a blunt warning from the US leader.

"They're not going to be restarting anything. If they restart it, they're going to have big problems, bigger than they ever had before. And you can mark it down," Trump said.

The disagreement threatens to plunge transatlantic relations to their lowest point since the Iraqinfo-icon Warinfo-icon, despite the lavish welcome Trump put on for Macron's state visit.