Iran has sent its response to US proposals to end the war via mediators in Pakistan, Iranian state media report.
No details have been released. The US has not made details of its proposals public, either, but reports suggest they centre on a 14-point memorandum of understanding, which could lead to negotiations on Iran's nuclear ambitions.
A ceasefire meant to facilitate talks to end the war launched by the US and Israel in February has been largely observed, despite occasional exchanges of fire.
However, Iran has continued to block the Strait of Hormuz - leading to a rise in world oil prices - and the US has been enforcing a blockade of Iranian ports to exert pressure on Tehran to agree to its terms.
The US naval blockade has infuriated Iran.
