China Has Had a Spy Base in Cuba for Years, U.S. Official Says

A Chinese spy base in Cuba that could intercept electronic signals from nearby U.S. military and commercial buildings has been up and running since or before 2019, when the Chinese base was upgraded, according to a Biden administration official.

The official, speaking on the condition of anonymity to discuss sensitive intelligence, said the spy base was an issue that the Biden administration had inherited from former President Donald J. Trump. After Mr. Biden took office, his administration was briefed about the base in Cuba as well as plans China was considering to build similar facilities across the globe, the official said.

The existence of an agreement to build a Chinese spy facility in Cuba, first reported on Thursday by The Wall Street Journal and also reported by The New York Times and other news outlets, prompted a forceful response from Capitol Hill. In a joint statement, Senator Mark Warner, Democrat of Virginia and chairman of the Senate Intelligence Committee, and the panel’s top Republican, Senator Marco Rubio of Florida, said they were “deeply disturbed by reports that Havana and Beijing are working together to target the United States and our people.”

John Kirby, the National Security Council spokesman, denied the reports at the time, saying they were “not accurate.” He added that “we have had real concerns about China’s relationship with Cuba, and we have been concerned since Day 1 of the administration about China’s activities in our hemisphere and around the world.”

But a U.S. official familiar with the intelligence cited in Thursday’s reports insisted that China and Cuba had struck an accord to enhance existing spy capabilities.

Carlos F. de Cossio, a deputy foreign minister of Cuba, wrote on Twitter on Saturday that the latest reports on spying facilities were “slanderous speculation.”

Some of the Biden administration’s critics in Congress questioned the motives for the administration’s response.

“Why did the Biden administration previously deny these reports of a C.C.P. spy base in Cuba? Why did they downplay the ‘silly’ C.C.P. spy balloon?” Representative Mike Gallagher of Wisconsin, the Republican chairman of the House select committee looking into strategic competition with China, said in a statement Saturday, referring to the Chinese Communist Party by its initials.

The Biden administration has been working to counter China’s continued efforts to gain a foothold in the region and elsewhere, an administration official said, chiefly by engaging diplomatically with nations that China was pursuing as potential hosts for such bases. The official added that the administration had slowed China’s plans but declined to give specifics.

While Beijing’s global efforts to build military bases and listening outposts have been documented previously, the reports detailed the extent to which China is bringing its intelligence-gathering operations into ever-closer proximity with the United States. Cuba’s coastline is less than 100 miles from the nearest part of Florida, a close enough distance to enhance China’s technological ability to conduct signals intelligence, by monitoring the electronic communications across the U.S. southeast, which is home to several military bases.

China and the United States routinely spy on one another’s activities, and Cuba proximity has long made it a strategically valuable foothold for U.S. adversaries, perhaps most famously during the Cold War, when the Soviet Union attempted to store nuclear missiles on the island nation during the Cuban Missile Crisis.

A spokesman for the Chinese Foreign Ministry, Wang Wenbin, said Friday in response to the reports, “The U.S. is the global champion of hacking and superpower of surveillance.”

The reports also surfaced at an awkward moment for the Biden administration, which has been trying to normalize relations with China after a protracted period of heightened tensions. Last year, several diplomatic, military and climate engagements between the two countries were frozen after Speaker Nancy Pelosi visited Taiwan over objections from Beijing, which considers the self-governing island part of its territory.

High-level meetings, including an official trip by Secretary of State Antony J. Blinken, were canceled again earlier this year, after a Chinese spy balloon was seen crossing the United States by people on the ground, and tracked hovering near sensitive military sites.

Mr. Blinken is now scheduled to travel to Beijing for meetings that begin June 18, and it is unclear if revelations of a Chinese spy facility so close to U.S. territory could complicate those plans. Other issues hover over the trip, including growing calls for China to release Yuyu Dong, a prominent journalist who has been detained since February last year and is awaiting trial on charges of espionage that his family members say are false. Mr. Dong, a former Nieman fellow at Harvard, met for years in a transparent manner with American and Japanese diplomats and journalists in Beijing.