New Delhi, June 19 -- US Vice President JD Vance said on Thursday (June 18) he may delay a planned trip to Switzerland for a ceremonial signing of the Iran-US agreement, adding fresh uncertainty to the rollout of the deal aimed at ending the conflict.

"Our plan is to go to Switzerland. I don't know exactly when," Vance told reporters at the White House, adding, "I suspect this weekend, but I'm not sure."

The visit was expected to help formally launch the next phase of negotiations between Washington and Tehran.

President Donald Trump said the agreement had already been signed and was designed to prevent economic fallout from the war, which had driven oil prices higher and rattled markets.

Trump said the deal would avoid "economic cata...