Iran has sent its response to a US ceasefire proposal to end the West Asia conflict amid the rising tensions, according to an Iranian state media report on Sunday.
"The Islamic Republic of Iran sent today through Pakistani mediators its response to the latest text proposed by the United States to end the war," the official IRNA news agency said, without offering details.
The development came shortly after Iran warned the US that it would no longer hold back from retaliatory strikes, even as Gulf countries reported attacks, including one on a freighter sailing towards Qatar.
The United Arab Emirates accused Iran of being behind an attack that targeted its territory, in what would be, if confirmed, only the second alleged strike on Gulf countries since the start of a month-old ceasefire.
Tehran's military chief Ali Abdollahi met the country's supreme leader Mojtaba Khamenei and, according to Iranian state television, received "new directives and guidance for the continuation of operations to confront the enemy."
This came as South Korea reported unidentified aircraft had hit a cargo vessel in the Strait of Hormuz last week, and Qatar's defence ministry said a freighter arriving in the country's waters from Abu Dhabi was hit by a drone on Sunday northeast of the port of Mesaieed.
The United Kingdom Maritime Trade Operations centre said the bulk carrier reported being struck by an unknown projectile. "There was a small fire that has been extinguished, there are no casualties. There is no reported environmental impact," it said.