China has been spying from Cuba for some time, US official says

China has been spying from Cuba for some time and upgraded its intelligence collection facilities there in 2019, a Biden administration official said on Saturday, following a report about a new spying effort underway on the island.

The Wall Street Journal on Thursday reported that China had reached a secret deal with Cuba to establish an electronic eavesdropping facility on the island roughly 160km from Florida, but the US and Cuban governments cast strong doubt on the report.

The Biden administration official, speaking on condition of anonymity, said the media's characterisation "does not comport with our understanding", but did not specify how the report was wrong nor address in detail whether there were efforts by China to build a new eavesdropping facility in Cuba.

The official said the issue predated Joe Biden's presidency, as had Beijing's efforts to strengthen its intelligence collection infrastructure worldwide.

"This is an ongoing issue, and not a new development," the official said. "The PRC (People's Republic of China) conducted an upgrade of its intelligence collection facilities in Cuba in 2019. This is well-documented in the intelligence record."

Asked for comment, an official at China's embassy in Washington pointed to Friday's statement by a Chinese foreign ministry spokesperson who accused the US of "spreading rumors and slander" with talk of a Cuba spy station, and of being "the most powerful hacker empire in the world."

The Cuban government did not immediately respond to a request for comment. On Thursday, Cuban Vice Foreign Minister Carlos Fernandez de Cossio dismissed the Journal's report as "totally mendacious" and called it a US fabrication meant to justify Washington's decades-old economic embargo against the island. He said Cuba rejects all foreign military presence in Latin America and the Caribbean.

Attention surrounding alleged Chinese spying from Cuba comes as Washington and Beijing are taking tentative steps to soothe tensions that spiked after a suspected Chinese high-altitude spy balloon crossed the US before the US military shot it down off the East Coast in February.

That includes a trip to China that US officials say Secretary of State Antony Blinken is planning for June 18. Washington's top diplomat had earlier scrapped the visit over the spy balloon incident.

The Biden administration official said that despite the former administration of Donald Trump being aware of the Chinese basing effort in Cuba and making some attempts to address the challenge, "we were not making enough progress and needed a more direct approach."

The official said US diplomats had engaged governments that were considering hosting Chinese bases and had exchanged information with them.

"Our experts assess that our diplomatic efforts have slowed the PRC down," the official said. "We think the PRC isn't quite where they had hoped to be."