U.S. President Donald Trump promised on Thursday “major military punishment” for Iran and its Houthi allies, after the Yemeni fighters struck two Saudi oil tankers in the Red Sea, extending the Middle East war to a second major shipping chokepoint.

The prospect that disruption could widen to a second sea sent global oil prices surging in one of the steepest rises of the war. Brent crude LCOc1 rose more than 6%, breaking through $100 a barrel for the first time since May.

Two weeks since the effective collapse of an interim truce meant to end the war, the U.S. military launched another nightly round of air strikes on Iran, prompting Iran to fire at neighbouring Arab countries that house U.S. bases.

After the Houthis said they had struck the two tankers, Trump said he would hold Iran accountable for any further attacks by the fighters. The Houthis, who control northern and western Yemen, said this week they were imposing a naval blockade on Saudi Arabia, which has diverted millions of barrels of oil per day by pipeline to the Red Sea to get around Iran’s blockade of Gulf oil through the Strait of Hormuz.

“If they do this again, the U.S. will hold Iran responsible, in that the Houthis are a Surrogate and/or Proxy of Iran, and major military punishment will be inflicted upon Iran and, of course, the Houthis, themselves,” Trump wrote on Truth Social.

U.S. Secretary of State Marco Rubio told a diplomatic gathering in Southeast Asia the price Iran pays “will get higher every night” until Tehran is ready for a peace deal it would live by.

“Iran is begging (for a deal) every day. The problem with Iran is every time they make a deal … they either break it or they want to change it,” he said. “And maybe they’ll change their mind here over the next few days as they continue to suffer great losses.”

The Houthis said their forces had carried out missile and drone strikes on Saudi oil tankers, the Encelia and the Layla.

A maritime security source said the Encelia had transmitted a distress call reporting it had been struck by a missile near the Saudi port of Jizan in the Red Sea just north of Yemen late on Wednesday. Saudi state news agency SPA said the strike had caused a fire at the bow.

Reuters could not immediately confirm the attack on the Layla but Trump mentioned two attacks on Saudi tankers.

Houthi attacks could close the strait known as the Bab el-Mandeb or “Gate of Tears” which controls access from the Red Sea to the Indian Ocean, the second most important route for energy shipments after the Strait of Hormuz at the mouth of the Gulf.

IRAN STRIKES JORDAN, KUWAIT

Meanwhile, Iran said it attacked U.S. missile systems, weapons and fuel storage sites in Jordan, as well as U.S. military posts in Kuwait.

Jordan’s army said it engaged four Iranian missiles and six drones in the past 24 hours, intercepting all but one missile, which fell in an uninhabited area.

Iranian military spokesperson Brigadier General Mohammad Akraminia said Iran would keep retaliating as long as the U.S. continued to attack its infrastructure and coastal areas, Iranian state TV reported.

Since the United States and Israel began the war in February, Iran has demonstrated that it can hit U.S. targets in the region, despite Trump having claimed early on that the U.S. had wiped out Iranian military capabilities.

Four people familiar with U.S. intelligence said Iranian strikes on CIA targets earlier in the war had prompted U.S. intelligence to investigate whether Russia was assisting Iran with targeting information or drone technology.

OIL PRICES STOKE INFLATION

High oil prices are stoking inflation globally, and have put Trump’s Republican allies under pressure ahead of congressional elections in November.

In the days since the Houthis announced their blockade in the Red Sea, several tankers have changed course to avoid the Bab el-Mandeb, heading north instead through the Suez Canal, potentially using a much longer and more expensive route to reach Asian customers by sailing around Africa.

Two Chinese supertankers carrying a combined 4 million barrels of oil were attempting to exit the Red Sea via the Bab el-Mandeb Strait on Thursday, shipping data showed.

The Houthi threat to impose a naval blockade against Saudi Arabia could significantly widen the war and strain the U.S. military, current and former U.S. officials said.

TRUMP THREATENS INFRASTRUCTURE

Last month’s interim deal to halt fighting has collapsed over the Strait of Hormuz, where Iran aims to assert control over Gulf energy exports by requiring ships to sail close to its coastline and eventually charge transit fees.

It has fired on ships that use an alternative channel further from its coast, promoted by Washington.

Trump vowed on Wednesday to destroy an Iranian bridge or power plant every time Iran shoots at a ship in the Strait of Hormuz. Iran’s joint military command in turn warned it would target regional oil, gas, electricity and economic infrastructure and prevent the export of “even a single drop of oil,” Iranian state media reported.