Treasury Secretary Scott Bessent on Monday will announce sanctions against Iran in an effort to isolate the country economically, amid failed efforts by the U.S. to end its roughly six-month war with Iran with a combination of truces and air attacks. 

“At dawn begins an economic D-Day – the single greatest financial offensive ever marshaled against an adversary,” Bessent said in an op-ed in The Financial Times on Sunday. 

He is set to announce the Trump administration plan at a press conference Monday afternoon.

Bessent told CNBC that the Trump administration wants U.S. allies and the rest of the world to stop doing business with Iran, and the administration plans to use all its resources against anyone who doesn't comply with the directive. 

"We are going to them and saying you are either with us or against us,” Bessent said. 

Trump last week threatened to target Iran with "crushing" economic sanctions, and he threatened severe financial penalties against any nation that helps Iran skirt the sanctions.