Washington, Aug. 24 -- The US Treasury Department is set to unveil new sanctions against Iran on Monday as President Donald Trump's administration steps up economic pressure on Tehran after months of military confrontation and stalled negotiations.

Treasury Secretary Scott Bessent has described the measures as the "single greatest financial offensive ever marshalled against an adversary," while Trump has warned of an "economic D-Day" for Iran.

Bessent said the latest measures would "squash" the Iranian economy and reduce Tehran's ability to finance its military and regional proxy groups.

Trump has separately warned countries against giving Iran an economic "lifeline," threatening "tremendous economic consequences" without specifying whic...