Signatories to the Iran nuclear deal on Wednesday said they wished to preserve it after Tehran said it would no longer respect certain "voluntary commitments" that were made.
Iran also warned that it would begin high level uranium enrichment within 60 days if signatory states did not protect it from US sanctions.
France, Britain, Germany, Russia and China are all signatories to the 2015 nuclear deal from which the US withdrew last year. All have said they wish to keep the accord alive but renewed sanctions imposed by Washington have had a severe effect on Iran's economy.
Trump imposes more sanctions, but with a twist
On Wednesday, Donald Trump imposed fresh sanctions of Iran's revenue from exporting industrial metals. The move affects Iran's iron, steel, aluminium, and copper sectors. The earnings from metal industry are Tehran's biggest source of export revenue after selling oil.
Trump said that Iran "can expect further actions unless it fundamentally alters its conduct."
However, Trump also said he was willing to negotiate.
"I look forward to someday meeting with the leaders of Iran in order to work out an agreement and, very importantly, taking steps to give Iran the future it deserves," he said.
US' Iran envoy warns against attack on US forces
Separatelly, a US representative slammed the Iran announcement as "an attempt to hold the world hostage."
Talking to reporters on the phone, US Special Envoy for Iran, Brian Hook, said the US will continue putting maximum pressure on Tehran until it chages its behavior. He said Iran could change its foreign policy, but did not provide specifics. He also said Iran had not shown signs of violating the nuclear deal, but added that US sanctions were producing "positive impacts."
Hook warned the Islamic Republic against targeting US forces in the Middle East, after the US deployed an aircraft carrier strike group to the area.
"Any attack will be met with force," he said.
Germany determined to save the deal
German Defense Minister Ursula von der Leyen said Europe had to "do everything" to maintain dialogue with Iran. "Stable relations" were paramount, she told DW, calling for cooperation with Iran to work "within the framework of the deal."
Social Democrat (SPD) lawmaker and foreign policy expert Rolf Mützenich told DW that "even though the hardliners in Tehran weren't able to push through their demands to ignore the treaty, the latest move has a destabilizing effect on the region. Together with other signatories on the UN Security Council, Germany must do everything it can to rescue parts of the deal. Even if that means a US veto."
Europe has a "strong interest" in saving the deal, Green party parliamentarian Omid Nouripoor told DW. "It could distance itself from US policy that dictates Saudi Arabia is our most important ally in the Middle East.
Bijan Djir-Sarai, the head of the Bundestag's German-Iranian parliamentary group and the foreign policy spokesperson for the opposition FDP, said Tehran's step would spell the end of the nuclear deal.
"The Europeans have done everything to keep this agreement alive, but at the end of the day, Iran closed the door," he told DW.
France and EU make an 'assessment'
The announcement was met with a measured response from France.
French Defense Minister Florence Parly said she wanted to keep the nuclear deal intact, but stressed that Iran's scaling back of commitments might mean sanctions would have to be re-imposed.
"These are some of the things that will be examined," she told France's BFM TV news channel.
"If these commitments are not respected, naturally this question would be asked," she added.
A senior EU official said Brussels was still in an "assessment phase” to determine whether sanctions should be re-imposed. Any EU-wide action would need to be agreed by all member states.
After visiting Iran's neighbor Iraq, US Secretary of State Mike Pompeo arrived in London on a diplomatic visit that was expected to cover Iran.
Russia criticizes US 'pressure'
The Kremlin said there were no alternatives to the Iran nuclear deal at present, and denounced "unreasonable pressure" that caused Tehran to suspend some of its commitments.
"Putin has repeatedly spoken about the consequences of ill-considered steps towards Iran, meaning the decision taken by Washington" to reimpose sanctions, Kremlin spokesman Dmitry Peskov said.
Russia would work with European countries to maintain the "continued viability" of the deal, Peskov said. He added that it was too early to discuss the possibility of Moscow joining sanctions against Tehran.
Russian Foriegn Minister Sergei Lavrov said European signatories should fulfil their obligations under the pact.
China calls for restraint, not sanctions
Beijing said the nuclear pact would need to be upheld and urged restraint.
"Maintaining and implementing the comprehensive agreement is the shared responsibility of all parties," said Chinese foreign ministry spokesman Geng Shuang at a regular press briefing.
"We call on all relevant parties to exercise restraint, strengthen dialogue, and avoid escalating tensions," he said, adding that China "resolutely opposes" unilateral US sanctions against Iran.
Read more: What is Iran's Revolutionary Guard?
Israel restresses long-term stance
Israeli Prime Minister Benjamin Netanyahu responded by reiterating a long-held position — that his country would not allow Iran to obtain nuclear weaponry.
"This morning, on my way here, I heard that Iran intends to pursue its nuclear programme," Netanyahu said in a speech to mark Israel's Memorial Day. "We will not allow Iran to achieve nuclear weaponry. We will continue to fight those who would kill us."
What might happen next?
German Middle East expert Michael Lüders told German broadcaster Deutschlandfunk that it was difficult to predict how the situation might develop.
"There is no longer any kind of direct channel of communication between Washington and Tehran. There's no red telephone, so if there is a crisis it could erupt in a serious and violent way," Lüder said. "The European Union, which is a cosignatory of the nuclear treaty with Iran, is in a miserable situation. Neither Great Britain, France nor Germany — the three crucial signatory states — have so far clarified how they plan to act in this dispute, or signaled to the US that they are not happy with this policy of confrontation."
rc,dj/jm (AFP, dpa, Reuters, AP)