The United States on Monday threatened Iran with what it called “the greatest financial offensive ever marshaled” as it prepared to roll out economic sanctions that target Iran’s trade partners in an attempt to pressure the Islamic Republic into favorable terms to end the war.

US Treasury Secretary Scott Bessent will hold a press conference on later Monday amid promises to reveal even more severe measures on a country that has endured near-continuous economic sanctions since the Islamic Revolution of 1979.

“At dawn begins an economic D-Day — the single greatest financial offensive ever marshaled against an adversary,” Bessent wrote in an opinion piece published in the Financial Times.

Without detailing specific measures, Bessent signaled the US will 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.