HAVANA (AP) — Four Russian ships, including a nuclear-powered submarine, will arrive in Havana next week, Cuban officials said Thursday, citing “historically friendly relations” between both nations and as tensions escalate over Western military support for Ukraine in its war with Russia.

Cuba’s foreign ministry said in a news release that the ships will be in Havana between June 12 and June 17, noting that none of them will carry any nuclear weapons and assuring their presence “does not represent a threat to the region.”

The announcement came a day after U.S. officials said that Washington had been tracking Russian warships and aircraft that were expected to arrive in the Caribbean for a military exercise. They said the exercise would be part of a broader Russian response to the U.S. support for Ukraine.

The officials said that the Russian military presence was notable but not concerning. However, it’s taking place as Russian President Vladimir Putin has suggested that Moscow could take “asymmetrical steps” elsewhere in the world in response to President Joe Biden’s decision to allow Ukraine to use U.S.-provided weapons to strike inside Russia to protect Kharkiv, Ukraine’s second-largest city.

Cuba’s Foreign Ministry said that the four Russian ships are the frigate “Gorshkov,” the nuclear-powered submarine “Kazan,” the fleet oil tanker “Pashin” and the salvage tug “Nikolai Chiker.”

During the fleet’s arrival at the port of Havana, 21 salvos will be fired from one of the ships as a salute to the nation, which will be reciprocated by an artillery battery of Cuba’s Revolutionary Armed Forces, the foreign ministry said.