CAIRO/WASHINGTON — Iran promised to retaliate against expanded U.S. sanctions that the Americans said would cut Iran's economic lifeline, with Tehran expressing confidence that major trading partners would resist Washington's pressure campaign. U.S. Treasury Secretary Scott Bessent unveiled the measures on Monday but stopped short of the most punishing sanctions, saying countries that continued trading with Iran risked being forced out of the dollar-based financial system. Bessent declined to identify the countries that would be targeted or reveal when the penalties would take effect, saying he would instead give them time to comply with the new directive. The Treasury Department did announce new sanctions on 60 individuals, entities and vessels, but the list did not feature any of the Chinese financial institutions suspected of facilitating Iran's oil trade. Iran and the United States signed an interim deal in June aimed at ending the war that began with U.S. and Israeli attacks on Iran, but the Islamabad memorandum, as it is known, quickly faltered. Mediator Pakistan made "signific