Both Havana and Washington have denied press reports that China is planning to set up an observation base in Cuba off the U.S. coast.

Cuban Deputy Foreign Minister Carlos Fernandez de Cosio said in a statement read to the press on Thursday that the Wall Street Journal published on the eighth of June a completely false and unfounded information that there is an agreement between Cuba and China in the military field to establish a supposed espionage base.

Cuba rejects any foreign military presence in Latin America, including the many military bases and troops (of the United States), he said, adding that "slanders of this kind are often fabricated by American officials."

The Wall Street Journal reported that Beijing and Havana have struck a secret agreement to set up a Chinese eavesdropping facility on the Caribbean island, enabling Beijing to monitor communications across the southeastern United States.

In the eastern United States, the headquarters of the Army Southern and Central Command, both in Florida, are located.

The newspaper quoted unnamed U.S. officials as saying that China would pay Cuba billions of dollars in exchange for the facility.

Earlier, White House National Security Council spokesman John Kirby denied the reports. In a statement to MSNBC, Kirby said, "I have seen that report. It's not accurate."

"What I can say is that we have been concerned from day one under this administration about Chinese influence activities around the world, certainly in this hemisphere, in this region," he said. "We are watching this closely."

Pentagon spokesman Pat Riley called the Wall Street Journal report inaccurate.

"We are not aware of China and Cuba building any spy station of any kind," he said, adding that "the relations that these two countries have are something that we are constantly monitoring."

It comes amid strained relations between Washington and Beijing over U.S. support for autonomy for Taiwan, which China says it is determined to restore by force if necessary.

Chinese President Xi Jinping is pushing for expanding his country's security presence around the world to keep pace with the widespread deployment of the U.S. military on all continents.

A Chinese base in Cuba, just 150 kilometers off the south coast of Florida, would pose the biggest direct threat yet to the U.S. mainland.

The Soviet Union had electronic espionage facilities in Cuba to monitor the United States, but when Moscow established a nuclear missile base in Cuba in 1962, the United States imposed a blockade on the island, which threatened to clash with the two superpowers at the time, before reaching an agreement to resolve the crisis, the Soviet Union withdrew nuclear missiles from Cuba while Washington withdrew its nuclear-capable missiles from Turkey after the Soviets considered them a threat to them.

Reports of China's move in Cuba come after a Chinese balloon was spotted at high altitudes over the United States earlier this year, crossing from west to east over sensitive military installations before being shot down by a U.S. fighter jet off the east coast.