New Delhi, Aug. 20 -- The United States is preparing a sweeping new economic campaign against Iran, with Treasury Secretary Scott Bessent warning allies and China that they must support Washington's efforts or face consequences.

The escalation comes as President Donald Trump seeks to increase economic pressure on Tehran after months of military strikes and a US blockade that have disrupted Iranian oil exports.

Bessent said Washington was preparing what he described as an unprecedented coordinated campaign to isolate Iran economically.

"This is going to be the greatest coordinated economic isolation in the history of the world," Bessent was quoted as saying by CNBC.

He said the message to US allies was effectively: "You are either with...