The United States is entering the "endgame" of its war with Iran, Treasury Secretary Scott Bessent said on Sunday, as he prepared to unveil what he called the toughest sanctions in history against Tehran.
"At dawn begins an economic D-Day - the single greatest financial offensive ever marshaled against an adversary," Bessent wrote on X.
He is due to present the new measures at a press conference on Monday.
Bessent said US President Donald Trump has "dismantled Iran's military capabilities," destroyed nearly 100% of its military factories and "buried its nuclear program."
"We are now entering the endgame," he said.
Trump on Wednesday announced an "economic D-Day" for Iran and threatened supporters of Tehran with drastic measures.
"Those who fear the danger of defying Tehran ought not to discount the cost of testing Washington," Bessent wrote on X.
"Our objective is to sever every economic lifeline that sustains the tyrannical regime until Tehran stands alone," he added.