In 2005, Venezuela formed the Petrocaribe alliance with Caribbean nations agreeing to buy below market oil on a deferred payment arrangement (1% interest for 25 years on the balance).
Facing its own economic collapse, Venezuela halted oil shipments through the program last, leaving economically challenged nations to fend for themselves. Haiti has been particularly hard hit. The government agency responsible for keeping the lights on quickly ran out of funds when having to buy oil on the open market. Now transportation throughout the Caribbean nation has come to a stop with no end in sight to the fuel shortage. Here