DUBAI-Another oil tanker was struck near the Strait of Hormuz overnight amid a high-stakes standoff between the U.S. and Iran to squeeze each other economically.

U.S. Treasury Secretary Scott Bessent ramped up the rhetoric in President Trump's pressure campaign this week with vows to crack down on countries that do business with Tehran. Iran has threatened to retaliate by hitting American interests and further choking off energy flows from the Persian Gulf if the U.S. doesn't back off.

Iran throttled traffic in the strait with attacks on ships beginning early in the six-month war. The latest strike came as fresh diplomatic efforts failed to produce a tangible breakthrough.

Pakistan's army chief, Asim Munir, met Iranian leaders in Tehran on Monday to discuss ending the war and reopening the strait. Pakistan reported significant progress but mediators said the talks produced no substantive breakthrough and failed to persuade Tehran to restart negotiations with Washington.

The U.K. Maritime Trade Operations, which is affiliated with the Royal Navy, said early Tuesday that an oil tanker was struck by an unknown projectile off the coast of Oman, damaging its engine room and leaving the vessel unable to operate. The crew was reported safe.

No one immediately claimed responsibility for the attack or was publicly blamed. Iran has targeted more than a dozen commercial vessels near Hormuz or the Red Sea so far this month and has threatened others as part of its effort to control traffic.

Pressure is also building across other key oil-export routes in the region. A Saudi tanker was struck Monday in what the Iran-backed Houthi militia in Yemen said was an attack they carried out with a ballistic missile. UKMTO said the strike caused a fire on the tanker's main deck.

The Houthis declared a blockade on Saudi ships last month and began launching attacks, as Iran has sought to raise the economic pressure on the U.S. by widening the scope of disruptions to the Red Sea route Saudi Arabia has been using to get around the blockage in Hormuz.

"Our enemies want to launch an economic terrorist attack against us," Iranian Economy Minister Ali Madanizadeh said, according to state news agency IRNA. "This time, they should not think that our approach will be defensive and that we will only defend ourselves. They should also expect an attack from us."

With diplomacy stalled nearly six months into the war, the Trump administration has shifted to trying to strangle Iran's remaining trade and financial links while keeping oil flowing from the Gulf, betting that tighter sanctions and financial isolation will force Tehran back to the table.

Bessent said Monday that the U.S. is launching a new campaign dubbed "Operation Economic Outcast" to isolate Iran, warning that countries and companies that continue doing business with Tehran could face sweeping U.S. penalties.

Residents of Tehran reported long lines to buy gasoline on Tuesday as people rushed to get ahead of limited supplies, a declining currency and the threat of further sanctions.

The Trump administration has hinted again over the past week at the on-again, off-again goal of regime change. The president said early Tuesday on social media that the Iranian government is creating a humanitarian crisis that must be stopped. Bessent said Thursday in an interview with CNBC that, "We are going to collapse this regime."

Tehran is betting that pressure on Gulf shipping and energy flows can raise the global cost of Washington's efforts, punish countries that cooperate with it and inflict political pain on Trump ahead of the U.S. midterm elections by putting pressure on Gulf shipping and energy flows.

Iran's recently created agency, the Persian Gulf Strait Authority, identified 46 vessels it says violated its rules for crossing the strait and threatened them with fines, detention or seizure of their cargoes. It also warned that vessels that did business with those ships could face penalties as well.

Iran's top security official, Mohsen Rezaei, said Sunday that Iran will regard any country's support for Washington's economic campaign as an act of war.

"If the economic war continues, not a single drop of oil will be exported, neither through the Strait of Hormuz nor from anywhere in the Persian Gulf," Rezaei wrote in a post on social media.

While flows through the strait have fallen sharply during the conflict, some crude and oil products are still getting out with help from the U.S. Navy. Saudi Arabia and the United Arab Emirates have also kept exports moving through pipelines that bypass the waterway.

China poses the biggest test of the new U.S. campaign as it usually buys most of Iran's oil exports, while Chinese banks and other entities help move revenues back to Iran. When asked whether the U.S. would sanction Chinese banks that do business with Iran, Bessent said that no one is out of reach.

On Tuesday, a Chinese Foreign Ministry spokesman said that economic warfare will only heighten tensions and could disrupt the global economy. China "will take all necessary measures to firmly safeguard its rights and interests," Lin Jian said.