Donald Trump says he will end the thaw between the US and Cuba if the country 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.
The president-elect threatened in a tweet to put an end to the detente following the death of Fidel Castro.
But the White House bristled at Mr Trump’s warning, saying the president was not concerned about the threat.
White House Press Secretary Josh Earnest told reporters that reversing the policy would be “a significant economic blow” to Cubans and was “not as easy as a stroke of a pen”.
President-elect Trump tweeted he would “terminate” Mr Obama’s policy on normalising relations with Cuba as thousands of Cubans queued to pay their respects to former President Fidel Castro who died on Friday.
They gathered in Havana’s Revolution Square as part of farewell commemorations which lasted until Tuesday night, when foreign leaders are due to arrive in Cuba to pay their respects.