US Secretary of State Marco Rubio expressed cautious optimism on Thursday about diplomatic efforts to end the war with Iran, saying there were signs of progress while warning against excessive expectations.
Speaking before departing for a NATO meeting in Sweden, Rubio said there were "some good signs" in the negotiations. However, he added that he did not want to be "overly optimistic."
Rubio also repeated the US assessment that Iran's leadership system was "itself is a little fractured" and stressed that US President Donald Trump preferred a negotiated settlement.
"But if we can't get a good deal, the president's been clear, he has other options," Rubio said.
Trump recently renewed threats of military strikes against Iran after negotiations over a permanent end to the conflict, started by the US and Israel in late February, stalled. He later said he had postponed a planned new US attack earlier this week because serious negotiations were under way.
Speaking at the White House, Trump reiterated that Iran must hand over its stockpile of highly enriched uranium.
"We're not going to let them have it," Trump said.
The fate of roughly 400 kilograms of highly enriched uranium held by Tehran has emerged as one of the main sticking points in the negotiations.
