The United States maintains robust and enduring sanctions against Cuba. Some of the sanctions are pursuant to executive order, and thus can be strengthened or relaxed depending on the policies of the President. Others are laws passed by the US Congress and codified as Federal Regulations, which are, by their nature, more permanent than executive orders (though enforcement may differ depending on who occupies the White House). Despite the broad scope of US sanctions against Cuba, certain trade is licensed (i.e., permitted), including with respect to agriculture.
In general, the UN, EU and UK do not maintain sanctions against Cuba. However, the US government has applied sanctions extra-territorially to non-US companies it believes are subject to US jurisdiction. As such, all vessel owners, charterers and traders, including those non-domiciled in the US, should gauge their exposure to US sanctions before agreeing to call at Cuba.