The prohibitions in § 546.201 on transactions or dealings involving blocked property apply to transactions by any U.S. person in a location outside the United States with respect to property held in the name of a person whose property and interests in property are blocked pursuant to § 546.201 , or property in which a person whose property and interests in property are blocked pursuant to § 546.201 has or has had an interest since the effective date.
31 C.F.R. §546.406