Iran Foreign Ministry spokesperson warned Monday that Tehran would respond harshly to expanded U.S. sanctions, including measures against countries it sees as cooperating with Washington.
"Any escalation of this situation will undoubtedly bring about consequences," Esmail Baghaei said. "Our hands are not tied."
The new head of Iran’s top security body warned Sunday that Tehran will see any country’s support for the sanctions as an "act of war."
The expanded sanctions come after weeks of impasse. The United States has not dislodged Iran’s grip on the Strait of Hormuz, through which a fifth of the world’s traded oil passed before the war started nearly six months ago.
Iran's demands for reopening the strait include lifting the U.S. naval blockade, withdrawing U.S. forces from the region and reparations for damages sustained in the war.
It has held separate talks with Oman, on the other side of the strait, on jointly managing the waterway regardless of whether a new deal is brokered with the U.S.
Sanctions have historically raised prices of basic goods in Iran, but after decades of withstanding them, Iran’s economy has adapted through finding new trading partners and building domestic industries.
Ahead of the expected U.S. announcement, the country's currency hit a record low on Monday.
Meanwhile, Pakistan's army chief Asim Munir, who has built a personal rapport with U.S. President Donald Trump, arrived in Iran on Monday for talks, Iranian media said.
Pakistan said the visit was part of its efforts "to promote regional peace and stability," and a Pakistani source said Munir was expected to meet people close to Iran's supreme leader.
Two Pakistani sources said Trump had called Munir last week, with another saying the main request was to bring Iran back to negotiations. The White House did not immediately respond to a request for comment.
The U.S. and Iran have not conducted airstrikes on each other's militaries for weeks, but their last official face-to-face talks to end the six-month-old conflict took place in June and strikes on vessels in the Strait of Hormuz have continued.
A projectile struck a tanker west of the Saudi port city of Yanbu in the Red Sea on Monday, causing a fire on the main deck, shipping monitors from the United Kingdom Maritime Trade Operations said. They did not say who had launched the projectile. Iran's Houthi allies last month said they would block Saudi oil exports diverted to the Red Sea to avoid Hormuz.
Thousands of people have died, most of them in Iran and Lebanon, since the U.S. and Israel began strikes on Feb. 28, degrading much of Iran's conventional military capacity and inflicting economic pain while killing Iran's then-Supreme Leader Ayatollah Ali Khamenei.
Yet Iran has preserved enough missile and drone capability to attack its Gulf neighbors and bring shipping in the Strait of Hormuz to a near standstill, pushing up world fuel prices. The exact state of Iran's nuclear program, which the Americans and Israelis aim to wipe out, remains unknown.
Oil prices eased Monday after two weeks of gains as investors took profits ahead of the expected U.S. announcement.
Without detailing specific measures, Bessent signaled the U.S. would target "fearful nations" that practice "appeasement" by engaging with Iran's economy and financial system.
"They would do well to consider the consequences of sustaining it," he wrote in the Financial Times.
Iran has been bracing for the sanctions for days, issuing a series of statements hinting at a major military response.
