Iran's IRNA says it will not join second round of US talks, citing excessive demands and shifting US stance.
US President Trump accuses Iran of ceasefire violation, warns of possible military action and targets key infrastructure if talks fail.
Deputy Foreign Minister Saeed Khatibzadeh says no date set for next round; both sides must agree on framework before negotiations resume.
US Energy Secretary Chris Wright says negotiations are progressing, calls Trump a 'creative negotiator', expects Hormuz shipping to resume soon.