Iran's president said his country would never surrender, as the military continued to trade with Israel and retaliate against a number of Gulf states.
Massoud Pezeshkian spoke less than a day after US President Donald Trump said his government would not negotiate with Tehran without its "unconditional surrender."
But in a televised address on state television, Pezeshkian said: "They will take their dreams of our unconditional surrender to the grave."
A three-member leadership council has been in power since the assassination of Supreme Leader Ali Khamenei a week ago, until a successor is named. It includes Pezeshkian - a relative moderate - as well as the hardline head of the judiciary, Gholamhossein Mohseni Ejei, and senior cleric Alireza Arafi.