Primary sanctions generally apply to US persons or to situations where there is a US nexus (such as the involvement of a US person, US-originating goods or transactions that take place within US borders).

Secondary sanctions authorize OFAC or the US State Department to threaten sanctions on a person - even a non-US citizen - for a specified activity. Sanctions are intended to discourage non-US persons from engaging in specific transactions, even if these transactions are not subject to primary sanctions.