The Islamic Republic displayed its military might, parading thousands of troops through the streets of the capital, Tehran, along with military hardware.
The recent surge of violence in Syria lays bare the challenges interim leader Ahmed al-Sharaa faces in delivering on his promise to lead a more unified country.
Defense Minister Israel Katz said parts of the Palestinian enclave would be "annexed to Israel" unless the remaining 59 captives, dead and alive, were freed.
Hamas said Israel had violated the ceasefire agreement, “exposing the prisoners in Gaza to an unknown fate,” while Israel said it would act “with increasing military force.”
The stock of uranium enriched to up to 60% fissile purity, close to the roughly 90% of bomb grade, has been a long-standing concern for Western powers.