Negotiations under way in Vienna, aimed at ending international concerns over Iran’s nuclear program, reached a crucial stage on Wednesday, as diplomats began writing a final deal that none were sure they could successfully complete.

Optimism broadly expressed by diplomats at the table that a deal could be reached by a self-imposed July 20 deadline has “gotten way out of control,” a senior US administration official told journalists in Austria, as the fourth round of comprehensive talks began.

“As this process moves forward, there will be a lot of noise out there – some of you might even make [it],” the official, intimately involved in the negotiations, said. “There will also be speculation about where the sticking points remain."

“I cannot advise you strongly enough not to buy into that kind of speculation,” the official added.

The official spoke on the condition of anonymity in order to keep the focus of talks on the diplomatic process.

Prime Minister Binyamin Netanyahu continued to warn the West against signing a “bad deal,” stressing in interviews with the Japanese media that the goal of the talks should be to “prevent Iran from having the capacity to make nuclear weapons.”

What Tehran is seeking to achieve, he said during his visit to Tokyo in an interview with NHK, the Japanese Broadcasting Corporation, is relief of the sanctions regime, while retaining its nuclear capabilities.

While the US delegation refuses to publicly discuss the issues under contention in Vienna, some others – including their consultants, Middle East allies and negotiating partners across the table – have fewer reservations about talking to the press.

Among the issues those parties raise: Concern over whether Iran will ever admit to its nuclear weaponization program, as uncovered by the UN’s International Atomic Energy Agency.

Another of the many issues at play is the number of centrifuges, which can enrich uranium to bomb-fuel quality, that will be allowed to remain in Iran under an agreement.

Iran has refused to dismantle its nuclear infrastructure, which includes more than 10,000 operating centrifuges and a heavy-water plutonium plant under construction, providing its government with a second possible path to nuclear warheads.

Iran’s Supreme Leader Ayatollah Khamenei refuses to include its ballistic missile program in the nuclear negotiations.

And the Islamic Republic’s research and development on nuclear technology, too, will be a core issue in the final talks.

Throughout his visit to Japan, Netanyahu has drawn parallels between Iran and North Korea, as well as between Japan’s concerns about the North Korean nuclear program, and Israel’s fears about Iran’s nuclear development.

“The result of a bad agreement could be that Iran would be able to do with the world what North Korea did here, to make an agreement that keeps it very close to [building] the bomb, and then break out at an appropriate time when the world’s attention is riveted to another crisis. And the outcome, if that happens, would be very bad, and it would be like North Korea,” he said.

Netanyahu, in an interview with the Mainichi Shimbun newspaper, said that Iran and North Korea were already working together, dubbing it “cooperation between the two great terrorist states of our time.” Whatever the Iranians have, “they will share with North Korea,” he said.

Israel has made clear that it feels that the Western powers erred in not putting Tehran’s weapons program on the agenda of the talks toward a final accord, and in the interview Netanyahu once again sounded the alarms.

The P5+1, he said, “should insist that Iran stops developing ICBMs, in addition to dismantling its capacity to make atomic bombs and atomic warheads. Why do they need ICBMs? You don’t develop ICBMs to carry a few kilograms of TNT for thousands of kilometers. You develop it only for one purpose: for nuclear weapons.”

An interim deal struck last November by the P5+1 (the US, Russia, China, UK and France, plus Germany) and Iran expires on July 20, and extending it would probably complicate the diplomatic effort.

A spokesman for EU foreign policy chief Catherine Ashton, who coordinates diplomacy with Iran on behalf of the six powers, said negotiators held a “useful initial discussion” on Wednesday morning and would hold coordination meetings later in the day.

“We are now hoping to move to a new phase... In which we will start pulling together what the outline of an agreement could be. All sides are highly committed,” Michael Mann said.

Meanwhile, in Jeddah on Wednesday, US Secretary of Defense Chuck Hagel urged Saudi Arabia and its Gulf neighbors to unite in confronting common threats such as Iran, even as the Arab states struggle to overcome divisions over Qatar’s support for the Muslim Brotherhood in Egypt.

“The most pressing security challenges threaten this region as a whole – and they demand a collective response,” Hagel said during opening remarks of a meeting of defense ministers from the Gulf Cooperation Council.

“This approach is how the region must continue to address the threats posed by Iran,” he said.

Most of the GCC’s six members – Saudi Arabia, Kuwait, Bahrain, Qatar, the United Arab Emirates and Oman – are wary of Iranian influence in the Middle East, but their responses vary from barely concealed hostility to diplomatic engagement.

Reuters contributed to this report.

Please LIKE our Facebook page - it makes us stronger