U.S. Senator Bill Nelson sent letters to the chief executives of 10 major U.S.-based airlines on Monday, urging them to cap airline fares for passengers fleeing Hurricane Maria so that confusion over cost does not delay evacuations, an aide said.

"I urge you to begin the process now for implementing capped airfare," Nelson said in his letter, noting that Maria is already a major hurricane. "Individuals and families should not be forced to delay or cancel their evacuation efforts because of confusion over the cost of airfare."