Iran warned it must make concessions for deal by John Kerry

Iran and the United States traded warnings of the consequences of failure yesterday as negotiators arrived in Vienna for a final round of nuclear talks aimed at securing a historic deal by a July 20 deadline.

We’re hopeful that we can make progress in narrowing those gaps and pursuing that comprehensive solution but the Iranian side is going to have to take additional steps that it should be able to take,” Ben Rhodes, the US deputy national security adviser, said. “This has been a top priority for our administration.”

Ayatollah Ali Khamenei, Iran's Supreme Leader has given his backing to the negotiations but the stakes are high for Iran and the West as the end nears. The Gulf nation’s economy, driven by the world’s No. 4 oil reserves, has been wracked by sanctions limiting trade and undermining its currency. For world powers, failure to peacefully resolve suspicions over Iran’s nuclear program could build on mounting Middle East tensions spreading from Syria to Iraq.

“The decisive time approaches when the temporary nuclear deal could be turned into a global solution,” Javad Zarif, the Iranian foreign minister, wrote Le Monde newspaper. “I press them to not allow illusions to derail a process that will allow an end to a pointless crisis and an opening to new horizons.”

John Kerry, the US Secretary of State, writing in the Washington Post, said that the negotiations constituted "a choice for Iran's leaders".

"They can agree to the steps necessary to assure the world that their country's nuclear program will be exclusively peaceful and not be used to build a weapon", Kerry wrote. "[Or] they can squander a historic opportunity to end Iran's economic and diplomatic isolation and improve the lives of their people."

While the sides have made progress toward increasing transparency into Iran’s nuclear work and modifying a reactor to make it less susceptible to making nuclear weapons, gaps remain over the amount of enriched uranium the country should produce. Iran wants capacity to produce more fissile material for power plants. The U.S. wants Iran to reduce existing enrichment abilities and cap future expansion.

In his essay, Zarif warned the West against repeating “missed opportunities” of the past and pointed to a two-year span of negotiations from 2003 until 2005. Those talks crumbled after European negotiators rejected an Iranian offer to limit the number of centrifuges — the fast-spinning machines that enrich uranium — in operation to 3,000. Today, Iran has 19,000 of the devices installed.

“No one can go back in time,” Zarif said. “Sacrifices were made, our capacities are today considerably different. No one can make them disappear with a wand.”

Kelsey Davenport, Arms Control Association analyst, said the prospects for a deal were good. She said: "There is a lot of time left for diplomacy and a good comprehensive nuclear agreement is within reach, despite significant gaps between the two sides on core issues."