Donald Trump has threatened tariffs on any country providing oil to Cuba. Venezuela and Russia have historically supplied oil to Cuba, but are already subject to extensive sanctions and tariffs. Following the US military's seizure of ousted Venezuelan President Nicolas Maduro earlier this month, Trump has repeatedly spoken about taking action against Cuba. The oil shipments from Mexico have been scrutinized after Trump vowed to stop Cuba from receiving oil and money from Venezuela. The US and Mexican government are preparing for negotiations later this year on their trilateral trade deal with Canada.