If you have been waiting since last year for the first commercial flight between Philadelphia and Cuba, it's not happening.

Frontier Airlines, which won permission for weekly trips between Philadelphia International Airport and Camaguey, Matanzas, and Santa Clara, Cuba, is pulling out of Cuba altogether.

Frontier will end its Miami to Havana route on June 4 because of overcapacity — too many flights — to the island nation, and higher-than-expected costs of operating at the Havana airport, said airline spokesman Jim Faulkner.

A new era of U.S.-Cuba travel was expected, with hundreds of scheduled flights a week ending a 55-year-old trade embargo on Cuba. The U.S. Department of Transportation in June approved six U.S. carriers to begin scheduled air service.

But seven months after JetBlue Airways became the first U.S. airline to land in Cuba, Frontier and Silver Airways are ending service to the island.

"Lack of demand coupled with overcapacity by the larger airlines has made the Cuban routes unprofitable for all carriers," said Misty Pinson, spokeswoman for Silver, which will suspend Cuba service on April 22.

American Airlines, with a hub in Philadelphia, is reducing frequencies to some destinations, and switching to smaller aircraft on a few routes.

American had 1,920 seats a day to Cuba until February, when it cut the number to 1,472. American will have 1,368 daily seats to Cuba next month.

U.S. carriers flocked to get slots, or gate rights, after the Obama administration and Cuba signed an agreement reestablishing scheduled passenger air service for the first time in more than 50 years.

"As markets develop we have to align our flights with what the market is showing us," said Martha Pantin, American spokeswoman. "We need to remain competitive in the market, and that's why we reduced service."

American has four daily flights from Miami to Havana and one flight a day from Charlotte, N.C. to Havana.

Starting April 4, American's regional partner, Republic Airways, will fly 76-seat planes instead of 128-seat aircraft between Miami and Camaguey and Cienfuegos, Cuba. "American is going to retain that route authority, but Republic will provide the service. We've been going with a bigger aircraft. Now we're going with a regional flight," Pantin said.

The United States continues to ban tourism to Cuba, but allows 12 categories of travel, including family visits, official business, journalist visits, professional meetings, religious activities, and "people to people" cultural and educational trips.

Frontier found the costs "to turn an aircraft" in Havana, such as landing, gate, and ground fees, were "significantly higher than we assumed," said Faulkner, the spokesman.

"The market conditions failed to materialize," he said. "There was just so much excess capacity allocated to the Florida-Cuba market."

JetBlue is continuing to operate nearly 50 weekly round-trips to Cuba, but on smaller aircraft effective May 3, a spokesman said.

"I think airlines always saw Cuba as a long-term play, but I have to imagine it's been worse than they expected to be pulling service to the degree they have," said Seth Kaplan, managing partner of Airline Weekly, an industry publication.

"The simplest reason is that they can't get enough people to fly there. As to why, it's a combination of factors," Kaplan said. "The tourism infrastructure in Cuba is spotty. Some people worry, 'OK, if I go there, is it going to be the same kind of experience I'd have at another destination?' And there's still some ambiguity about 'What if someone accuses me of being just a regular tourist and I'm not supposed to be there.'"

In addition, Americans cannot use U.S. bank-issued credit cards in Cuba. "You have to pay cash. Do you want to travel with $2,000 in your wallet?" Kaplan said. "So it's a combination of some perception issues, and some realities like the inability to use a U.S.-issued credit card that make it a very different place from other destinations."