Guantanamo Bay, Cuba - Cubans on Tuesday protested against the presence of a US nuclear-powered submarine last week at the American naval base in Guantánamo Bay on the island's east coast.

In a statement issued in English, the foreign ministry said it "strongly rejects the arrival of a nuclear-powered submarine in the Guantánamo Bay on July 5, 2023, that stayed until July 8 at the US military base located there."

The incident was a "provocative escalation of the United States, whose political or strategic motives are not known," it added.

The ministry warned of the "danger of the presence and circulation of nuclear submarines of the United States armed forces in the nearby Caribbean region."

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The US State Department said it does not discuss the movement of US military assets.

But spokesperson Matthew Miller said the US position is that "we will continue to fly and sail and otherwise move military assets wherever it is appropriate to do so under international law."

Cuba has been suffering crippling US sanctions and hostility that President Joe Biden has continued from his predecessor Donald Trump, who chose to reclassify the island nation as a "state sponsor of terrorism." The move was a reversal of the Barack Obama administration's rapprochement with Cuba.

The regime has since deepened ties with China and Russia.

Moscow and Havana were at the center of a global nuclear weapons scare in 1962, when the Soviet Union stationed missiles on the island, in response to the US government placing missiles in Italy and Turkey, sparking threats of an attack by the US.

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The weapons were withdrawn and a military clash was averted, but Cuba has been under a US blockade ever since.

Cuba has repeatedly demanded the return of a 45-square-mile territory in US hands since 1898 and home to the Guantánamo base.

Since 2002, it has been used by the US to house "enemy combatants" captured in what it called the "war on terror" following the September 11, 2001, attacks.

Last month, UN Special Rapporteur on Human Rights Fionnuala Ni Aolain said the treatment of the remaining 30 detainees at Guantánamo was "cruel, inhuman, and degrading."