Beijing and Havana are longtime socialist allies, and Chinese authorities have consistently opposed the economic blockade imposed on the island for decades by the United States.

Tensions have intensified this month as US President Donald Trump warned that Cuba "is ready to fall".

Trump has told Havana to "make a deal" or pay a price similar to Venezuela, whose former leader Maduro was captured in a US bombing raid on January 3 that killed dozens of people.

"China expresses its deep concern and opposition to the United States' actions" on Cuba, foreign ministry spokesman Guo Jiakun said Tuesday at a regular press conference.

"We urge the United States... to stop undermining regional peace and stability," said Guo, also calling on Washington to "immediately lift the blockade and sanctions against Cuba".

"China will continue to provide Cuba with as much support and assistance as possible," he said.

Politico reported last week that the Trump administration is considering a naval blockade to halt all imports of oil into Cuba.

The report cited a person familiar with the plan as saying: "Energy is the chokehold to kill the regime."

Cuban President Miguel Diaz-Canel on Saturday supervised military exercises, describing them as a deterrent against potential aggression from the United States.