U.S. Secretary of State Antony Blinken said Monday that China conducted an upgrade of its intelligence collection facilities in Cuba in 2019.
Blinken told reporters that when the Biden administration took office in January 2021, it was briefed on a "number of sensitive efforts by Beijing around the world" to expand China's overseas operations for collecting intelligence.
He said the administration of former President Donald Trump was aware of the issue and that the Biden administration concluded Washington was not making enough progress on the matter.
Since that time, Blinken said, the United States has been implementing a new strategy that has been yielding results.
"I can't get into every step that we've taken. But the strategy begins with diplomacy," he said.
Blinken said the United States has engaged at high levels with governments that are considering hosting Chinese bases. He said U.S. experts have determined the diplomatic efforts slowed down China's efforts to expand its intelligence-gathering activities.
China rejects the allegations that it has been carrying out an intelligence-gathering operation in Cuba, an island located about 160 kilometers from the southern U.S. state of Florida.
Chinese foreign ministry spokesperson Wang Wenbin said Monday at a news briefing that the allegations about a Cuban spying effort were false and that the United States was giving inconsistent and contradictory information.
Earlier in the day, a U.S. official said China's intelligence-gathering operation in Cuba was "well-documented" when President Joe Biden took office.
"This is an issue that this administration inherited," said the Biden administration official, who was not authorized to comment publicly about the matter and spoke on the condition of anonymity.
"It was our assessment that, despite awareness of the basing efforts and some attempts to address this challenge" during the White House tenure of Trump, "we were not making enough progress and needed a more direct approach," the official said.
The official said that since the U.S. changed its strategy, U.S. experts have assessed progress being made and that Beijing "isn't quite where they had hoped to be" in their spying efforts.
But the official said, "There are still challenges, and we continue to be concerned" about China's efforts in Cuba. China "will keep trying to enhance its presence in Cuba, and we will keep working to disrupt it."
In a Twitter post Saturday, Cuban Deputy Foreign Minister Carlos Fernandez de Cossío called the allegation "slanderous speculation."
The developments come as Blinken is expected to travel to Beijing next week.
His prior plans to visit China in February were canceled amid a spike in tensions as a Chinese spy balloon flew over the United States.
State Department Bureau Chief Nike Ching and Pentagon correspondent Carla Babb contributed to this article. Some information for this story came from The Associated Press and Reuters.
