When people break the law and run away from their home country, they are called fugitives. Some fugitives from the United States (which is a big country far away) have gone to Cuba (which is an island near Florida). Cuba is a different country with different laws.
Sometimes, fugitives go to Cuba because they don't think they will get in trouble there or because they don't want to go to jail in the United States. In Cuba, they can live without being arrested, even if they did something bad in the United States.
However, sometimes the United States government wants the Cuban government to send those fugitives back to the US to face their punishments. But, sometimes the Cuban government does not want to do this because they do not want to give up their own citizens who take refuge in the United States.
This can cause problems between the two countries and can affect how they work together. It is important for everyone to understand the laws of different countries and to face the consequences of their actions.