The United States is preparing to sharply increase economic pressure on Iran in a new campaign officials have called an “economic D-Day.” U.S. Treasury Secretary Scott Bessent said the planned measures would be the “single greatest financial offensive ever marshalled against an adversary.” The Trump administration says it wants to cut off the economic networks that help Iran continue trading with the outside world. Although the full details were still expected to be announced on Monday, August 24, the new measures could go beyond directly targeting Iran. They may also punish foreign countries, companies and other organizations that continue buying Iranian oil, transporting it, helping Iran move money or providing other economic services. This could include tougher secondary sanctions, meaning businesses and countries outside Iran could also face U.S. penalties if they continue important dealings with Tehran. Iran’s oil trade is expected to be a major focus, raising particular questions about China, one of Iran’s biggest economic partners and a major buyer of Iranian oil. The U.S. campaign comes as the conflict with Iran approaches its sixth month and diplomatic efforts remain stalled. Washington hopes the growing economic pressure will force Tehran to change its policies, including over its nuclear programme and the Strait of Hormuz, the crucial waterway used to transport large amounts of the world’s oil and natural gas. Iran, however, has rejected the U.S. threats. Iranian officials say the country has faced sanctions for decades and will not surrender because of more economic pressure. Tehran has also warned that if the economic campaign continues, it could take stronger action affecting oil exports from the Gulf, creating fresh concerns about global energy supplies. The pressure is already adding to Iran’s economic problems. Iran’s currency, the rial, fell to a new record low as the country waited for the new U.S. measures, while inflation and the wider effects of the conflict have made life increasingly difficult for ordinary people. The new sanctions could therefore become a major test for Iran, its trading partners and the global economy. If Washington takes action against countries and companies doing business with Tehran, the “economic D-Day” campaign could widen the conflict beyond the battlefield and increase tensions across the Middle East and global markets.