By Humeyra Pamuk, Dave Graham and Tala RamadanBUERGENSTOCK, Switzerland/DUBAI, June 22 (Reuters) - Iran-U.S. peace talks in Switzerland stretched into their second day on Monday, after a tense opening marked by Tehran's announcement it had again closed the Strait of Hormuz and U.S. President Donald Trump repeating his threats to resume attacks on Iran.

Iran to Send Delegation to Switzerland to Follow Up on U.S.-Iran Agreement, State Media Reports. Vance Says U.S. Officials on Ground for Iran Talks; No Evidence Tehran Is Closing…

US and Iranian officials are still expected to meet in Switzerland on Sunday, but Saturday's events point towards a likely major shift in the agenda for the first round of talks.