Six major powers meeting in Vienna have reached "substantial agreement" on a package of incentives and threats for Iran over its nuclear program, a senior US official said.
The official, speaking from Washington on condition of anonymity, said there was agreement with European powers Germany, France and Britain over the package of "carrots and sticks" for Iran.
Russia and China, which have been reluctant to support punitive measures against Iran, also appeared to be on board, he said.
"We have substantial agreement with the Russians and the Chinese. We are agreed certainly on the need for moving forward in the (UN) Security council if Iran doesn't respond to the offer," said the official.
Asked what substantial agreement meant, the official said he anticipated China and Russia would agree to most parts of the package but declined to discuss any specifics.
"I am hearing that it is going very well," he said, adding he had not been given a full account of the dinner where ministers met.