By Simon Lewis and Dave Sherwood WASHINGTON/HAVANA, Jan 15 - The U.S. State Department's top aid official on Thursday said Cuba's authorities must not interfere with a shipment of humanitarian aid to its people and suggested President Donald Trump could take action if Cuba does not comply.

President Trump stopped Venezuelan oil shipments to Cuba, and experts say disaster looms. Oil fuels its electric grid and without alternative supplies the country will plunge into extended darkness.

Though Mr Trump’s intentions are murky, it is obvious that Cuba’s regime is now unusually vulnerable. It has survived for decades by courting powerful backers like the Soviet Union to prop up its state-controlled economy.

Mexico, which was providing some oil to Cuba before Maduro's capture by the U.S., has become an especially key fuel supplier to the island since the Venezuelan leader's arrest, which was accompanied by the U.S. interception of vessels carrying oil to Cuba. Sheinbaum has referred to oil as "humanitarian aid."

The Soviet Union was Cuba’s benefactor for decades. Venezuela took up the slack, and Mexico has supplied “humanitarian aid.” But the world is changing rapidly, our columnist says.

President Donald Trump warned Cuba there will be no more oil coming its way and told it to strike a deal, inciting a response from its leaders.

President Donald Trump has urged Cuba to make a deal with the U.S. as he uses Venezuela to crank up the pressure on the island.

President Donald Trump said in a post on Truth Social that Cuba would no longer receive oil or money from Venezuela.

Cuban President Miguel Díaz-Canel says his administration is not in talks with the U.S. government. This comes a day after President Donald Trump threatened Cuba following the U.S. attack on Venezuela earlier this month.

The U.S. State Department's top aid official warned Cuba's authorities on Thursday not to interfere with a humanitarian aid shipment and suggested President Donald Trump could take action if Cuba fails to comply.