Originally Posted by
ajGoes
U.S. Customs and Border Protection's
Policies on importing goods from Cuba page says "It is illegal to import most goods from Cuba." Their page on
transiting with Cuban cigars puts it very clearly: "foreign nationals may not transit the U.S. with goods of Cuban origin." Note that although the page's title mentions cigars, the prohibition seems to cover everything. Sorry.
To be clear, when they say Cuban origin, that is exactly what they mean. If you bought a bottle of Cuban rum in Europe (never having been to Cuba), it would still be subject to confiscation upon entry to the US. It is the origin that counts, not where you bought it.