The US House of Representatives - one of two legislative bodies of the US government - has introduced a bill to sanction use by US persons of any cryptocurrency the Iranian government develops. The draft bill also requires a report on Iran's progress in developing said cryptocurrency within four months.
Sanctions against an Iranian crypto are part of a general increase in sanctions of Iranian entities. The bill - H.R.7321, entitled “Blocking Iran Illicit Finance Act” - names a number of additional Iranian banks to sanction and makes a number of modifications to already existing sanctions.
With respect to an Iranian state-backed cryptocurrency specifically, the bill states that:
All transactions related to, provision of financing for, and other dealings in Iranian digital currency by a United States person or within the United States are prohibited.
The law, should it be passed - which does not seem unlikely given the buildup of sanctions against Iran - described a civil penalty of up to $250,000 of fines; and criminal penalties of up to $1 million and up to 20 years in prison. These penalties are described in U.S. Code § 1705.
The US has lately been spearheading economic sanctions against Iran, Venezuela, and Russia. For example, the US recently strong-armed a keystone global financial messaging system, SWIFT, into blocking transactions with Iranian banks.
The universal reaction to sanctions is becoming cryptocurrency, even at the state-level. Following Venezuela’s example, Iran has begun active development of a cryptocurrency which the US now seeks to sanction; and Russia has also expressed interest in developing the capacity.