“It is impossible to predict the results, but we will stay very engaged with Iran,” said the U.S. administration official said.
“We hope Iran comes prepared and makes a concrete and substantive response” to a package proposed by world powers aimed at defusing the standoff, said the official who declined to be further identified.
Iran and the so-called P5+1 nations comprised of the five permanent U.N. Security Council members and Germany will sit down in the Kazakh city of Almaty from Friday for their fifth round of negotiations in the past two years.
The last talks held at the same venue in February saw the powers present Iran a proposal that would limit some sanctions in exchange for concession from Islamic Republic.
The powers are particularly concerned about Iran’s uranium enrichment to levels of up to 20 percent and the Fordo fortified bunker where such activity is conducted.
The powers also want Iran to ship out its existing stockpile of 20-percent enriched material.
The senior U.S. official said the powers had submitted “a balanced and very fair” proposal that is believed to include a lifting of some of the limits on Iran’s metals trading and small financial transactions.
The official refused to speculate about what would happen should Iran not accept the proposal’s terms or present its own unacceptable counter-offer.
Iran has already called the proposal “unbalanced” while describing the talks themselves as “positive.”
“I would hope that we are not at any last chance,” said the official.