By Humeyra Pamuk and Tala Ramadan

WASHINGTON/DUBAI/ISLAMABAD, April 30 (Reuters) - Iran said on Thursday that if Washington renewed attacks it would respond with "long and painful strikes" on U.S. positions, complicating U.S. plans for an international coalition to open the Strait of Hormuz.

Two months into the war that started with U.S.-Israeli strikes on Iran, the vital sea channel remains closed, choking off 20% of the world's supplies of oil and gas. That has sent global energy prices surging and heightened concerns about the risks of an economic downturn.

Efforts to resolve the conflict have hit an impasse, with a ceasefire in place since April 8 but Iran still blocking the strait in response to a U.S. naval blockade of Iran's oil exports, the country's economic lifeline.

U.S. President Donald Trump is slated to receive a briefing on Thursday on plans for a series of fresh military strikes on Iran in hopes of making Iran more flexible on nuclear issues in negotiations, Axios news site reported late on Wednesday.

That spurred big gains in oil prices, with the benchmark Brent crude contract hitting more than $126 a barrel at one point, its highest level since March 2022 after Russia's invasion of Ukraine. It later slipped back to $113 a barrel.

Any U.S. attack on Iran, even if limited, will usher in "long and painful strikes" on U.S. regional positions, a senior Revolutionary Guards official said.

"We've seen what happened to your regional bases, we will see the same thing happen to your warships," Aerospace Force Commander Majid Mousavi was quoted by Iranian media as saying.

AMAZON REPORTS DAMAGE TO CLOUD SERVICES

Brent prices have doubled since the U.S.-Israeli attack on Iran began on February 28, fuelling inflation and sending pump prices to politically painful levels worldwide.

As well as blocking almost all but its own shipping through the strait, Iran launched drones and missiles at Israel and U.S. bases, infrastructure and U.S.-linked companies in Gulf states.

Amazon AMZN.O on Thursday reported damage to its cloud regions in Bahrain and the United Arab Emirates from the conflict and said restoring normal operations could take months.

The company did not immediately respond to a Reuters query on when the damage took place and whether it was due to a drone attack or strikes nearby. A new Iranian strike would be a serious escalation given the ceasefire.

Tehran warned on Wednesday of "unprecedented military action" against continued U.S. blockading of Iran-linked vessels. The warning, together with the possibility of further U.S. military strikes, signalled more Middle East oil supply disruptions from a conflict that has killed thousands.

Another plan to be shared with Trump involves taking over part of the Strait of Hormuz to reopen it to commercial shipping, the Axios report added, saying such an operation may involve ground forces.

In a sign the U.S. was also envisaging a scenario where hostilities cease, the State Department cable invited partner countries to ‌join a new coalition called Maritime Freedom Construct (MFC) to enable ships to navigate the strait.

"The MFC constitutes a critical first step in the establishment of a post-conflict maritime security architecture for the Middle East," said the cable, which was due to be delivered orally to partner nations by May 1.

France, Britain and other countries have held talks on contributing to such a coalition but said they were only willing to help open the Strait when the conflict ends.

Supreme Leader Mojtaba Khamenei said in a written message to Iranians that Tehran would eliminate "the enemies' abuses of the waterway" under new management of the strait, indicating that the country intended to maintain its hold over it.

JAPAN SPEAKS TO IRAN ABOUT SAFE PASSAGE THROUGH STRAIT

Mediator Pakistan was trying to avoid escalation while the two sides exchange messages on a potential deal, a Pakistani source said on Wednesday. Trump has said Iran cannot have a nuclear weapon, while Tehran says its nuclear ambitions are peaceful.

Iran's latest offer for resolving the war, suspended since April 8 under a ceasefire deal, would set aside discussion of its nuclear program until the conflict is formally ended and shipping issues resolved.

That did not meet Trump's demand to tackle the nuclear issue at the outset.

The Pakistani source said the United States had shared "observations" on the Iranian proposal and it was now up to Iran to respond.

"(The) Iranians asked for time till the end of the week," the source told Reuters.

German Chancellor Friedrich Merz said Tehran should stop playing for time, and Japanese Prime Minister Sanae Takaichi said she had spoken to Iranian President Masoud Pezeshkian to ensure the safe passage of a Japanese-related vessel and all others through the strait.

Trump on Tuesday discussed with U.S. oil companies how to mitigate the impact of a possible extension of the U.S. blockade on Iranian ports for months if needed, the White House said on Wednesday.

U.S. intelligence agencies, tasked by senior administration officials, are also studying how Iran would respond if Trump were to declare a unilateral victory, two U.S. officials and a person familiar with the matter said this week.

Posted by: Alma Angeles/NET25 News