European leaders have pledged to remain committed to the Iran nuclear deal after US President Donald Trump dumped it as a "horrible, one-sided" agreement rooted in "fiction" and ordered the highest level of economic sanctions against Tehran.

Iran's Supreme Leader Ayatollah Ali Khamenei on Wednesday called Trump's Tuesday speech "silly and superficial" and said he was "making a damn mistake". He also said that he did not trust Britain, France or Germany and would need "guarantees" before continuing the nuclear deal.

Following Trump's announcement, the UK, France and Germany urged Washington not to obstruct the implementation of the Iran deal, also known as the Joint Comprehensive Plan of Action (JCPOA).

They said they would work with the other signatories to the agreement to stress continuing support for the accord. Iran -- in the 2015 pact with China, France, Russia, Britain, the US and Germany plus the EU -- had agreed to halt its nuclear programme in return for an easing of economic sanctions.

French Foreign Minister Jean-Yves Le Drian told RTL radio that "the deal is not dead. There's an American withdrawal from the deal but the deal is still there".

"President Emmanuel Macron would also speak to his Iranian counterpart, Hassan Rouhani, about our wish to stay in the agreement," he said, adding that there would be a meeting between France, Britain, Germany and Iran on Monday.

France also said it would do everything possible to protect European businesses after Trump warned he would seek to hit European firms that continued to trade with Tehran.

EU Foreign Ministers will meet their Iranian counterpart Mohammad Javad Zarif next week to offer personal reassurances they will take practical steps to protect the deal from sweeping US Treasury sanctions due to come into force over the next 180 days.

The Iranian President said his government remained committed to the nuclear deal with world powers, despite the US withdrawal. But he warned that Iran "was also ready to resume uranium enrichment if the accord no longer offered benefits".

In the Iranian Parliament, members burned an American flag.

Iranian Leader Khamenei said: "Trump, I tell you on behalf of the Iranian nation: You are making a damn mistake and you cannot do anything."

India called on all parties to "engage constructively" to resolve all contentious issues.

In a televised address, Trump said the US would withdraw from the "horrible, one-sided deal that should have never, ever been made" and that economic sanctions against Tehran would be reinstated.

Rather than protecting the US and its allies, he said it had placed "very weak limits on the regime's nuclear activity and no limits at all on its other malign behaviour, including its sinister activities in Syria, Yemen and other places".

Trump called the agreement "decaying and rotten" and "defective at its core".

The EU moved to protect the nuclear agreement by vowing to take steps to immunise European firms doing business with Tehran from any US sanctions. EU foreign policy chief Federica Mogherini said Europe will abide by the JCPOA.

Russia said it was "deeply disappointed" by Trump's decision. A meeting is scheduled between France, Britain, Germany and Iran on Monday.

Trump's predecessor Barack Obama, under whose administration the deal was signed, said Trump's announcement was "misguided" and "a serious mistake".

But the move was welcomed by Iran's major regional rivals, Saudi Arabia and Israel.

First Published:May 10, 2018 6:11 AM IST