Paloma Duarte, 18, a dancer, poses for a photograph in front of the Cuban and US flags in Havana, March 23, 2016. [Photo/Agencies]

WASHINGTON -- The first scheduled commercial flight from the United States to the Cuban capital Havana in more than half a century landed on Monday amid uncertainty about US President-elect Donald Trump's Cuba policy.

The American Airlines launched the flight from Miami, Florida, and it has more business plans to fly to Havana including a flight from Charlotte, North Carolina on Wednesday.

Earlier this year, several US airlines started flying routes to other cities of Cuba, which is some 145 km away from Key West, Florida.

Before the airliner landed in Havana, Trump tweeted that he might "terminate" the thaw in US-Cuba relations initiated by President Barack Obama.

"If Cuba is unwilling to make a better deal for the Cuban people, the Cuban/American people and the US as a whole, I will terminate deal," he said.

The tough comment requesting more concessions from Cuba is suggestive of a hard-line stance and is expected to raise more speculation and uncertainties about Trump's Cuba policy after the death of Cuban revolutionary leader Fidel Castro on Friday.

Washington resumed diplomatic relations with Cuba in July 2015, with its 55-year-long trade embargo against the Caribbean island nation still in place.

In 1961, Fidel Castro declared Cuba a socialist country. Before that, large-scale reforms he led, including nationalization of industries and banks, prompted Washington to sever ties.

Negotiations to normalize US-Cuba ties began since two years ago between Obama and Fidel Castro's brother Raul Castro, who succeeded him in 2006.