(BBC) - The US has stepped up its sanctions on Iran for "supporting terrorists" and pursuing nuclear activities.
The new measures target the finances of Iran's Islamic Revolution Guards Corps and three state-owned banks.
US Secretary of State Condoleezza Rice said the moves were part of "a comprehensive policy to confront the threatening behaviour of the Iranians".
The sanctions were backed by Britain, but a top Iranian MP dismissed them as a "strategic mistake".
The US declared the Revolutionary Guards a "proliferator of weapons of mass destruction", a reference to ballistic missiles they are allegedly developing, while their elite overseas operations arm, the Quds Force, was singled out as a "supporter of terrorism".
The US has repeatedly accused Iran of destabilising Iraq and Afghanistan, blaming the Revolutionary Guards for supplying and training insurgents.