difficult” while Steinmeier cautioned that the “final metres are the most difficult”. Even before a deal is sewn up, opponents have been lining up to criticise it, worrying it will not do enough to stop Iran getting the bomb.
These include US President Barack Obama’s Republican opponents and Israeli Prime Minister Benjamin Netanyahu, who on Sunday launched a blistering attack on the “dangerous” mooted deal.
“I just don’t understand why we would sign an agreement with a group of people who in my opinion have no intention of keeping their word,” US House Speaker John Boehner told CNN.
Israel is widely believed to be the sole, if undeclared, nuclear-armed power in the Middle East and has long been opposed to any Iran accord.
Saudi Arabia — leading an Arab coalition which on Monday carried out a fifth straight night of air strikes on Iran-backed rebels in Yemen — is also uneasy about any US-Iran thawing of ties.
Western diplomats say some areas in a highly complex jigsaw puzzle of an accord are tentatively agreed. But they caution there is a long way to go.
One said on Sunday that Iran had “more or less” agreed to slash the number of its centrifuge enrichment machines from 20,000 to 6,000 and to ship abroad most of its stockpile of low-enriched uranium.
This would make it a much more lengthy process to further purify these stocks to weapons-grade.
Iranian officials dismissed the numbers as “speculation”, with Araghchi ruling out sending the stocks abroad, although he said “other options” were being examined.
This could include diluting low-enriched uranium or converting it to another form.
But nevertheless Iranian officials have expressed guarded optimism that a breakthrough may be at hand.
“Getting to an accord is doable. Solutions have been found for numerous questions. We are still working on two or three issues,” Araghchi said.
In addition to scaling down its nuclear programme, the powers want Iran’s remaining facilities to be subject to an unprecedented level of inspections by the UN atomic watchdog.
Its underground facility at Fordo would also likely be barred from uranium enrichment, diplomats said, although it might be kept open for research purposes.
The US, EU and others are only prepared to suspend their sanctions, not terminate them, and in a phased manner in order to ensure that Iran does not violate the deal.
The issue of UN Security Council sanctions is particularly tricky.
Araghchi said on Sunday there must be a “precise framework” for lifting sanctions. The duration of any deal — the US wants at least 10 and possibly up to 15 years — is also a point of contention.