From left to right, spokesman for Iran's atomic agency Behrouz Kamalvandi, Iran's government spokesman Ali Rabiei and Iranian Deputy Foreign Minister Abbas Araghchi, attend a press briefing in Tehran, Iran, Sunday, July 7, 2019. The deputy foreign minister says that his nation considers the 2015 nuclear deal with world powers to be a "valid document" and seeks its continuation. (AP Photo/Ebrahim Noroozi)
From left to right, spokesman for Iran's atomic agency Behrouz Kamalvandi, Iran's government spokesman Ali Rabiei and Iranian Deputy Foreign Minister Abbas Araghchi, attend a press briefing in Tehran, Iran, Sunday, July 7, 2019. The deputy foreign minister says that his nation considers the 2015 nuclear deal with world powers to be a "valid document" and seeks its continuation. (AP Photo/Ebrahim Noroozi) Credit: Ebrahim Noroozi

Iran increased its uranium enrichment Sunday beyond the limit allowed by its 2015 nuclear deal with world powers, inching its program closer toward weapons-grade levels while calling for a diplomatic solution to a crisis heightening tensions with the U.S.

Iranโ€™s move, coupled with earlier abandoning the dealโ€™s limit on its low-enriched uranium stockpile, intensifies pressure on Europe to find any effective way around U.S. sanctions that block Tehranโ€™s oil sales abroad.

But the future of the accord that President Donald Trump unilaterally pulled the U.S. from a year ago remains in question. While Iranโ€™s recent measures could be easily reversed, Europe has struggled to respond, even after getting a 60-day warning about the increase.

Meanwhile, experts fear a miscalculation in the crisis could explode into open conflict, as Trump already has nearly bombed Iran over Tehran shooting down a U.S. military surveillance drone.

International reaction to Iranโ€™s decision came swiftly, with Britain warning Iran to โ€œimmediately stop and reverse all activitiesโ€ violating the deal, Germany saying it is โ€œextremely concerned,โ€ and Israeli Prime Minister Benjamin Netanyahu, a longtime critic of the accord, urging world powers to impose so-called โ€œsnapback sanctionsโ€ on Tehran.

The European Union says parties to the deal are discussing a possible emergency meeting after Iranโ€™s announcement, with EU spokeswoman Maja Kocijancic saying the bloc is โ€œextremely concernedโ€ about the move. There was no immediate response from the White House.

At a news conference, Iranian officials said the new level of uranium enrichment would be reached later in the day, but did not provide the percentage they planned to hit. Under the nuclear deal, the cap for enrichment was set at 3.67%, a percentage closely monitored by inspectors from the International Atomic Energy Agency, the U.N.โ€™s nuclear watchdog.

โ€œWithin hours, the technical tasks will be done and enrichment above 3.67% will begin,โ€ Iran nuclear agency spokesman Behrouz Kamalvandi said. โ€œWe predict that the IAEA measurements early tomorrow morning will show that we have gone beyond 3.67%.โ€

The IAEA said it was aware of Iranโ€™s comments and โ€œinspectors in Iran will report to our headquarters as soon as they verify the announced development.โ€

Ali Akbar Velayati, an aide to Supreme Leader Ayatollah Ali Khamenei, made remarks in a video Saturday about Iranโ€™s need for 5% enrichment. Bushehr, Iranโ€™s only nuclear power plant, is now running on imported fuel from Russia thatโ€™s enriched to around 5%.

Iranian Foreign Minister Mohammad Javad Zarif sent a letter to EU foreign policy chief Federica Mogherini outlining the steps it had taken, said Abbas Araghchi, a deputy foreign minister. Discussions with European powers are continuing and ministerial-level talks are planned later this month, he said.

โ€œWe will give another 60-day period, and then we will resume the reduction of our commitments,โ€ Araghchi said, without elaborating.

On Saturday, French President Emmanuel Macron told his Iranian counterpart, Hassan Rouhani, in a phone call that he is trying to find a way by July 15 to resume the dialogue between Iran and Western partners. It wasnโ€™t clear if July 15 carried any importance. The U.S. has called for a special IAEA meeting for Wednesday to discuss Iran.

Kamalvandi stressed that Iran will continue to use slower, first-generation IR-1 centrifuges to increase enrichment and will keep the number of centrifuges in use under the 5,060-limit set by the nuclear deal. Iran is barred from building and operating advanced centrifuges under the deal.

โ€œFor the enrichment we are using the same machines with some more pressure and some special technical work,โ€ he said. โ€œSo we donโ€™t have an increase in the number of centrifuges for this purpose.โ€

But Kamalvandi stressed that Iran is able to continue enrichment โ€œat any speed, any amount and any level.โ€

Enriched uranium at the 3.67% level is enough for peaceful pursuits but is far below weapons-grade levels of 90%.

The decision to ramp up uranium enrichment came less than a week after Iran acknowledged breaking the dealโ€™s 661-pound limit on its low-enriched uranium stockpile. Experts warn higher enrichment and a growing stockpile narrow the one-year window Iran would need to have enough material for an atomic bomb, something Iran denies it wants but the deal prevented.

The steps taken so far by Iran show it is more interested in applying political pressure than moving toward a nuclear weapon, said Daryl G. Kimball, the executive director of the Washington-based Arms Control Association. He said Iran would need at least 2,315 pounds of low-enriched uranium to make the core of a single nuclear bomb, then would have to enrich it to 90%.

โ€œIran is not racing toward the bomb as some allege but these are calibrated moves,โ€ Kimball told the Associated Press. However, โ€œif Iran and the United States remain on the current course, the agreement is indeed in jeopardy.โ€

Netanyahu urged the international community to punish Iran for its decision.

โ€œIt is a very, very dangerous step,โ€ he said. โ€œIโ€™m asking you, not to provoke but out of joint knowledge of history and what happens when aggressive totalitarian regimes can cross the threshold toward things that are very dangerous to us all. Take the steps that you promised. Enact the sanctions.โ€

However, Kimball cautioned against that.

โ€œIran is clearly not going to enter negotiations for a new deal if these sanctions are in place,โ€ he said. โ€œThis a self-made, Trump administration crisis because it has been taking drastic measures to dismantle the (deal) without a viable Plan B.โ€