The United States said Monday that Iran’s “nuclear blackmail” must be met with increased international pressure after Tehran announced earlier that it planned to exceed internationally agreed curbs on its stock of low-enriched uranium. “Iran’s enrichment plans are only possible because the horrible nuclear deal left their capabilities intact,” White House National Security Council spokesman Garrett Marquis said. “President Trump has made it clear that he will never allow Iran to develop nuclear weapons. The regime’s nuclear blackmail must be met with increased international pressure.” Britain said if Iran breached limits agreed under the deal then London would look at “all options”. Israeli Prime Minister Benjamin Netanyahu called for the immediate imposition of "snapback sanctions" if Iran breaks the stockpile limits set in the 2015 nuclear deal. "In any case, Israel will not allow Iran to obtain nuclear weapons,” he added. However European Union foreign policy chief Federica Mogherini said the EU would only react to any breach if the International Atomic Energy Agency formally identified one. French President Emmanuel Macron urged Iran to be "patient and responsible". "I regret Irans announcements today... We strongly encourage Iran to behave in a way that is patient and responsible," Macron said in a press conference at the presidential palace in Paris alongside his Ukrainian counterpart Volodymyr Zelensky. Macron said that any kind of escalation in the nuclear standoff at the current time was in the interest of no-one. "It is damaging to the interests of the Iranians themselves and also to the international community," he said. "So, we will do everything with our partners to dissuade Iran from this (surpassing the limit).” Tehran announced Monday that it would breach the curbs set in the 2015 Iran nuclear deal in 10 days. Tensions between Iran and the United States are rising more than a year after President Donald Trump announced Washington was pulling out of the so-called Joint Comprehensive Plan of Action and would begin reimposing sanctions on Tehran. The nuclear deal, reached during the presidency of Trump predecessor Barack Obama, requires Iran to curb its uranium enrichment capacity, capping Iran’s stock of low-enriched uranium at 300 kg of uranium hexafluoride enriched to 3.67 percent or its equivalent for 15 years. A series of more intrusive UN inspections under the deal have verified that Iran has been meeting its commitments. But US-Iran tensions are growing following accusations by Trump’s administration that Tehran last Thursday attacked two oil tankers in the Gulf of Oman, a vital oil shipping route. Iran denies having any role.