As deadline looms, Kerry says US in no rush to get Iran deal

Adding to signs that a deal was not close at hand, a top adviser to Iran's supreme leader was quoted by Iranian news agency Tasnim as saying Tehran's "redlines" should be respected in talks aimed at a deal under which Iran would curb its nuclear program in exchange for sanctions relief.

"A deal can be reached only if our redlines are respected," said Ali Akbar Velayati, the adviser to Supreme Leader Ayatollah Ali Khamenei. He also accused Kerry of making comments that were "part of America's psychological warfare against Iran."

Velayati's reported remarks came after a senior Iranian official in Vienna accused the United States and others nations of shifting their positions and backtracking on an April 2 interim agreement that was meant to lay the ground for a final deal.

"We're here because we believe we are making real progress," Kerry told reporters in the Austrian capital. "We will not rush and we will not be rushed."

However, Kerry said Washington's patience was not unlimited. We can’t wait forever," he said. "If the tough decisions don’t get made, we are absolutely prepared to call an end to this."

He did not say how much longer the talks could continue. Shortly after Kerry spoke, the White House said the talks would not likely drag on for "many more weeks."

Briefing reporters on condition of anonymity, the senior Iranian official sought to put the onus on the West for any failure to reach an agreement.

The official also said that Iran was looking forward to seeing whether the United States would "abandon its obsession with sanctions."

Negotiators have given themselves until the end of the day on July 10. But if a deal is not reached by 6:00 a.m. in Vienna (0400 GMT), the skeptical Republican-led U.S. Congress will have 60 days rather than 30 days to review it, extra time US President Barack Obama's administration worries could derail it.