Southwest Airlines will drop two secondary destinations in Cuba, as the US government continues to uphold a ban on tourist travel to the country.

The Dallas-based carrier will end service from Fort Lauderdale to Varadero and Santa Clara after 4 September. It will continue to fly to Cuba's capital, Havana, from Fort Lauderdale and Tampa.

"Our decision to discontinue the other Cuba flights comes after an in-depth analysis of our performance over several months which confirmed that there is not a clear path to sustainability serving these markets, particularly with the continuing prohibition in US law on tourism to Cuba for American citizens," says Southwest's senior vice-president of ground operations Steve Goldberg.

Southwest's exit from the two routes will leave JetBlue Airways as the sole carrier flying between Fort Lauderdale and Santa Clara, FlightGlobal schedules data show. No other airline operates between Fort Lauderdale and Varadero. American Airlines offers nonstop service from Miami to both Varadero and Santa Clara.

Southwest chief executive Gary Kelly said last month that demand to Varadero and Santa Clara was "very spotty and sometimes very light".

"What we need over a longer period of time is to be able to promote those destinations for tourism purposes," he said then. A continued ban on US tourism travel to Cuba will hurt US airlines' ability to further develop the market, said Kelly.

But a week after Kelly's remarks, US President Donald Trump said the US government will continue to enforce a ban on leisure travel by US citizens to Cuba - dashing the hopes of US airlines who were hoping otherwise.

US citizens are allowed to travel to Cuba under 12 categories designated by the US Treasury, which include official government business travel, educational activities and family visits among others.

Southwest is the latest US carrier to reduce service to Cuba, and is the first major US airline to drop destinations altogether. Spirit Airlines, Frontier Airlines and Silver Airways ended flights to Cuba in recent months.

Spirit and Frontier's exit had freed up route authorities to Havana, which several US carriers including Southwest have applied for.

Source: Cirium Dashboard