The US secretary of state says Pakistani officials will be travelling to Tehran today, telling reporters, “So hopefully that will advance this further,” Al Jazeera reports.

“The president’s preference is to do a good deal, that’s his preference. It’s always been his preference. If we can get a good deal done, that would be great,” Rubio said.

“But if we can’t get a good deal, the president has been clear – he has other options. I’m not going to elaborate on what those are, but everybody knows what those are.”

He added: “There are some good signs, but … I don’t want to be overly optimistic, as well, so let’s see what happens over the next few days.”