Just hours after two oil tankers were attacked in the Gulf of Oman on Thursday, leaving one ablaze and both adrift, Iranian Supreme Leader Ayatollah Ali Khamenei warned that while Tehran doesn't seek nuclear weapons, "America could not do anything" to stop Iran if it did.
The comments came during a one-on-one meeting capping Japanese Prime Minister Abe Shinzo's high-stakes visit in Tehran that sought to ease Iran-U.S. tensions, suggested the efforts had failed.
Khamenei told Abe during his visit to Iran that Tehran would not repeat its "bitter experience" of negotiating with the United States, state media reported.
"I do not see Trump as worthy of any message exchange, and I do not have any reply for him, now or in future," the Iranian leader said.
Benchmark Brent crude spiked at one point by as much 4% in trading following the suspected attack, to over $62 a barrel, highlighting how crucial the area remains to global energy supplies. A third of all oil traded by sea passes through the strait, which is the narrow mouth of the Persian Gulf.
The Front Altair, carrying petrochemical feedstock, was on fire in waters in the Gulf of Oman after an explosion that a source blamed on a magnetic mine. The Norwegian owner said its crew were safe.
A second Japanese-owned tanker was abandoned after being hit, the firm that chartered the ship said. The crew were also picked up.
Thursday's attacks were the second in a month near the Strait of Hormuz, a major strategic waterway for world oil supplies.
"We need to remember that some 30% of the world's (seaborne) crude oil passes through the Straits. If the waters are becoming unsafe, the supply to the entire Western world could be at risk," said Paolo d'Amico, chairman of INTERTANKO tanker association.
The United States and Saudi Arabia blamed Iran for limpet mine attacks in May on four tankers off the coast of the United Arab Emirates, a charge Tehran denies.
Tensions have risen since President Donald Trump, who has demanded Tehran curb its aggression and influence in the Middle East, pulled the United States out of a deal between Iran and global powers to curb Tehran's nuclear ambitions.
Thursday's attacks came as Japan's Prime Minister Abe Shinzo visited Tehran with a message from Trump and urged all sides not to let tensions escalate.
The Bahrain-based U.S. Navy Fifth Fleet said it was assisting the two tankers on Thursday after receiving distress calls. Britain said it was "deeply concerned" about Thursday's reported explosions and was working with partners on the issue.
Iranian Foreign Minister Mohammad Javad Zarif described the incidents as "suspicious" on Twitter, noting that they occurred during Abe's visit to Tehran. He called for regional dialogue.
Oman and the United Arab Emirates, in whose territorial waters the four tankers were hit in May, did not immediately issue any statements after Thursday's attacks.
Saudi Arabia and the UAE, both majority Sunni Muslim nations that have a long-running rivalry with predominantly Shiite Iran, have previously said attacks on oil assets in the Gulf pose a risk to global oil supplies and regional security.
Thursday's suspected attacks came a day after Yemen's Iran-aligned Houthi rebels fired a missile on an airport in Saudi Arabia, injuring 26 people. The Houthis also claimed an armed drone strike last month on Saudi oil pumping stations.
