FedEx Corp. dropped a plan to begin cargo flights to Cuba, as an opening between the U.S. and the communist country has foundered.

The courier “will not be filing for an extension of the startup date for U.S.– Cuba cargo air service between Miami and Varadero,” FedEx said in a statement Wednesday. The company is abandoning its right to fly five weekly frequencies and evaluating “alternative all-cargo service options to Cuba,” according to a letter to the U.S. Department of Transportation.

FedEx’s withdrawal ends more than two years of effort to start service to Cuba, which began as former President Barack Obama sought to normalize ties with the island. Relations have chilled under President Donald Trump, whose administration enacted new restrictions in 2017 on Americans traveling to Cuba and on the ability to do business with a list of government-controlled businesses.

The Memphis, Tennessee-based company won U.S. approval for cargo flights to Cuba in 2016. The following year, FedEx cited a series of obstacles to starting the service, including finding local partners and securing airport ground services. Cuba currently is listed by the carrier as among the countries it doesn’t serve.