Iran’s response to a US proposal to end the war has been sent via mediator Pakistan, according to Iranian state news agency IRNA.

The report said on Sunday that according to the proposed plan, the first stage of the negotiations will focus on ending hostilities, adding that Tehran’s response drew on ensuring “maritime security” in the Gulf and the Strait of Hormuz.

A Pakistani diplomatic source has told our colleagues at Al Jazeera Arabic that the Iranian response was delivered to the US side.

Washington sent Iran a 14-point proposal earlier this week. Under its conditions, Iran would have to agree to not develop a nuclear weapon and to stop all enrichment of uranium for at least 12 years.

It would also be required to hand over an estimated 440kg (970 pounds) stock of uranium, which it has enriched to 60 percent.

In return, the US would gradually lift sanctions, release billions of dollars in frozen Iranian assets, and halt its naval blockade of Iranian ports.

Al Jazeera’s Kamal Hyder in Islamabad said Pakistan had confirmed receipt of the Iranian response. He said that there was a sense of urgency to get the deal accepted, as the prolonging blockade of the Strait of Hormuz was having a critical impact on the world economy, especially in Pakistan.

“The stakes are very high: Pakistan is suffering economically as well. The fuel prices are sky-high,” he said.

“Pakistan has good relations with Iran, and it is in a favourable position with the Trump administration, so the likelihood of some sort of breakthrough is possible. The next few days will be critical and will depend on how favourably the US responds to whatever the Iranian response is,” Hyder concluded.