US president-elect Donald Trump says he will end the thaw between the US and Cuba if the Cuban government does not offer a “better deal”.

President Barack Obama has worked to improve relations with the communist government in Havana, culminating in his historic visit in March 2016.

But the president-elect threatened in a tweet to put an end to the detente.

His tweet came as thousands of Cubans queued to pay their respects to Fidel Castro, who died on Friday.

They gathered in Havana’s Revolution Square as part of farewell commemorations which will last until Tuesday night, when foreign leaders are due to arrive in Cuba to pay their respects.

A cortege will then transport his ashes east across the island to Santiago de Cuba, reversing the route Castro took during the Cuban revolution.

They will be laid to rest on Sunday in the city’s Santa Ifigenia cemetery.

In his tweet, Trump said that 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”.

On the campaign trail, Trump said that he would reverse President Barack Obama’s rapprochement with Cuba, which included the resumption of diplomatic relations, strengthening trade and lobbying the US Congress to terminate an economic embargo in place for 50 years.

His team has accused the Obama administration of giving too much away to Cuba without receiving enough in return.

Hours after Castro’s death was announced Trump released a statement calling him “a brutal dictator who oppressed his own people for nearly six decades”.

In a separate development the first scheduled flight to Havana in more than 50 years has departed from Miami, reports the BBC.

The American Airlines (AA) flight on Monday morning was the first of a new service to the Cuban capital which will fly from Florida four times a day.

“It’s a monumental day of gre