VIENNA    -   Representatives from Europe, China and Russia, which are still committed to the Iran nuclear deal, were meeting Sunday with Iran’s representative in Vienna to discuss how to salvage the unravelling accord.

The diplomats are examining issues linked to the implementation of the nuclear accord after Iran surpassed the uranium stockpile and enrichment limits set out in the 2015 deal.

Iran recently begun surpassing those limits, saying the moves can be reversed if other parties to the agreement — Germany, France, Britain, China, Russia and the European Union — come up with enough economic incentives to offset the US sanctions that President Donald Trump reinstated after pulling his country from the nuclear accord.

Experts warn that higher enrichment level and a growing uranium stockpile narrow the one-year window that Iran would need to have enough material to make an atomic bomb, something Iran denies it wants but that the deal prevented.

Last week, French authorities meeting with an Iranian envoy stressed the need for Tehran to quickly respect the nuclear accord it has breached and “make the needed gestures” to de-escalate mounting tensions in the Persian Gulf region.

Hours before Sunday’s meeting, Iran’s Deputy Foreign Minister Seyed Abbas Araghchi said in Vienna that, “in the last month, there have been a lot of developments regarding the (deal) that made it necessary to have another round of the Joint Commission meeting urgently,” Iran’s state-run IRNA news agency reported.

So far, neither Iran’s recent announcements that it had exceeded the amount of low-enriched uranium allowed under the deal nor its revelation it had begun enriching uranium past the 3.67% purity allowed, to 4.5%, are seen as such gross violations that they are likely to prompt Europe to invoke the deal’s dispute resolution mechanism.

Both of Iran’s actions have been verified by the U.N.’s nuclear watchdog, the International Atomic Energy Agency.

Iran, meanwhile, has taken increasingly provocative actions against ships in the Gulf, including seizing a British tanker and downing a US drone. The US has expanded its military presence in the region and fears are growing of a wider conflict.

A Royal Navy warship arrived Sunday in the Gulf to accompany British-flagged ships passing through the Strait of Hormuz. Britain’s Ministry of Defence said the HMS Duncan will join the Frigate HMS Montrose in the Gulf to defend freedom of navigation until a diplomatic resolution is found to secure the key waterway again.

Trump pulled the US out of the nuclear deal last year unilaterally, saying he wanted to negotiate a better one.

Under the provisions of the accord, signatories provided Iran with economic sanctions relief in exchange for curbs on the country’s nuclear program, but the latest US sanctions have highlighted the inability of the Europeans, as well as Russia and China, to keep up with their commitments.

Iran’s recent moves — which it defends as permissible after the US withdrawal — are seen as a way to force the others to openly confront the sanctions.

At the same time, Europe is under pressure from the US to abandon the Iran nuclear accord entirely and is also being squeezed by Iran to offset the ever-crippling effects of American economic sanctions.