Iran has sent its response to a United States proposal aimed at ending the war in the region, the Islamic Republic News Agency said on Sunday. The ?response, details of which are awaited, was sent to mediator ?Pakistan, and will ?focus at this stage ?on ?ending the war, IRNA said.

Earlier on Sunday, Iran reiterated that any attack on its oil tankers or commercial vessels would be met with attacks on US bases in the region and enemy ships. The warning came after US forces struck two Iranian oil tankers, claiming the vessels were trying to breach the US blockade of Iran's ports — while insisting a fragile month-old ceasefire remains in effect.

"Any aggression against our vessels will be met with a heavy and decisive Iranian response against American vessels and bases," Ebrahim Rezaei, spokesman for the Iranian Parliament's National Security and Foreign Policy Commission, wrote on social media, saying that as of Sunday, Tehran's "restraint is over".

On Sunday, a bulk carrier reported being struck by a projectile off Qatar's coast, the United Kingdom Maritime Trade Operations said. Also, the United Arab Emirates' air defenses dealt with ?two drones coming from Iran on Sunday, the latest ?in renewed attacks on the oil-rich Gulf country.

Since the US and Israel launched military strikes against Iran on Feb 28, Iran has largely blocked the Strait of Hormuz to global energy shipments. Saudi Aramco, a majority state-owned petroleum and natural gas company, said in a statement on Sunday that the world has lost around 1 billion barrels of oil over the past two months. Before the conflict, the narrow waterway carried one-fifth of the world's oil supply.

In another development, Iranian officials signaled an elevated strategic status for the strait, one that could rival the significance of Iran's nuclear program.

"In reality, it is a capability on the level of an atomic bomb, because when you have a capability that can affect the entire global economy with a single decision, that is an enormous capability," Mohammad Mokhber, who served as the acting president of Iran in 2024, told state-linked Mehr News Agency on Friday.

A Qatari liquefied natural gas tanker was sailing toward the strait on Saturday en route to Pakistan, according to LSEG shipping data. Sources said the move was approved by Iran to build confidence with Qatar and Pakistan, both mediators in the ongoing conflict. A ?Panama-flagged bulk carrier bound for Brazil ?passed through the Strait of ?Hormuz using a route designated by Iran's armed forces, ?Iran's semi-official Tasnim News Agency reported on Sunday.

Meanwhile, a CIA assessment indicated that Iran would not suffer severe economic pressure from the US blockade for about another four months, Reuters reported.

Separately, Russian President Vladimir Putin said on Saturday that Moscow is ready to transport and store Iran's stockpile of enriched uranium, adding that he hopes the conflict will end "as quickly as possible". There was no immediate comment from Iran.

The war will likely end in Washington's retreat, said Jeffrey Sachs, director of the Center for Sustainable Development at Columbia University, as the US cannot continue the conflict without triggering disastrous consequences.

"A renewed escalation would likely lead to the destruction of the region's oil, gas and desalination infrastructure, causing a prolonged global catastrophe. Iran can credibly impose costs that the US cannot bear and that the world should not suffer," he wrote in a commentary, coauthored with analyst Sybil Fares, for Al Jazeera on Saturday.

"The only path, and the one the US seems to be taking, is a retreat, with Iran in charge of the Strait of Hormuz, and with none of the other issues between the US and Iran settled," they added, calling it "neither a war of necessity, nor a war of choice — it was a war of whim. The underlying premise was hegemony".