A senior U.S. official on Tuesday cautioned against excessive optimism the nuclear talks with Iran, but said disputes could be overcome and a deal reached by a July 20 deadline, according to Reuters.
The official noted some media reports about the negotiations that have wrongly implied a deal called a "comprehensive plan of action" between Iran and the six powers was a virtual certainty.
"I've read a lot of the optimism you've written ... it's gotten way out of control," the official told reporters on condition of anonymity, ahead of the fourth round of negotiations.
"There are some very significant gaps (but) we can get to a resolution, I believe," added the official.
The official said delegations from Iran, United States, Britain, France, Germany, Russia and China would begin drafting an agreement this week that aims to cover specific curbs on Tehran's nuclear program in exchange for the gradual lifting of sanctions against Iran.
"Just because we will be drafting it certainly does not mean an agreement is imminent or that we are certain to eventually get to a resolution of these issues," the official added.
The comments came as top diplomats from Iran and the six world powers geared up for the crucial round of talks aimed at reaching a long-term deal.
This fourth round of talks in Vienna is aimed at transforming an interim deal struck in Geneva in November into a lasting accord.
The six powers want Iran to reduce the scope of its nuclear program in order to make any attempt to make a nuclear weapon practically impossible and easily detectable.
In return the Islamic republic, which claims its nuclear program is peaceful, wants all UN and Western sanctions lifted. Iran is gradually winning access to $4.2 billion of its oil revenues frozen abroad and some other sanctions relief.
Iran has not convinced everyone with its professed possession of a peaceful nuclear program, a doubt that was raised on Sunday when Iran's Supreme Leader, Ayatollah Ali Khamenei, said Western expectations that Iran limit its missile program were "stupid and idiotic." Similarly in January, Khamenei stated that negotiations with the US were a tactic to gain time.