The US Treasury plans new economic pressure on Iran, facing skepticism from critics. Targeting China's oil purchases poses risks to US-China relations and oil prices. Exchange houses in countries like the UAE help Iran move its funds. Secondary sanctions could pressure trading partners, including US allies like Turkey. The administration is considering various options to increase leverage against Iran.

Sustained naval blockade, more sanctions and making it harder for Tehran to sell its oil among the options to tighten the screws.

"It will be a combination of economic isolation like the world has never seen before, and the continued blockade in the Strait of Hormuz that will keep anything from going in or…

Remaining levers at President Donald Trump's disposal each carry a set of risks