Four Russian warships, including a nuclear-powered submarine, a frigate, an oil tanker and a rescue tug, arrived in Havana Bay, Cuba, on Wednesday, just 200 miles off the coast of Florida.

The submarine, identified as Kazan, a Yasen-class nuclear-powered cruise missile submarine, was welcomed with a 21-cannon salute and cheered on by the Cubans waving Russian flags.

Photos posted on the internet showed onlookers lined up along the seafront to watch the vessels arrive in the harbor. The Kazan is capable of carrying Zircon hypersonic missiles, but it’s unclear if it was armed with them.

However, U.S. and Cuban officials have confirmed that while the Kazan is nuclear-powered, it does not have nuclear weapons on board.

The Russian ships are expected to remain in Havana through the summer, possibly stopping in Venezuela. The warship’s arrival marks the latest in a series of Russian military exercises in the region, with Russian ships and submarines docking in Havana since 2008.

National Security Adviser Jake Sullivan told reporters on Wednesday that the U.S. is closely monitoring the Russian military drills in the Atlantic. He added that officials say there is no evidence of missile transfers from Cuba.

“We have seen this kind of thing before, and we expect to see this kind of thing again, and I’m not going to read into it any particular motives,” Sullivan said.

Experts believe Russia’s military in Cuba is a show of force by the Kremlin following the U.S. decision to allow Ukraine to use American-made weapons against Russian targets in the Kharkiv region.

According to Benjamin Gedan, director of the Latin America Program at the Wilson Center, the warship is a reminder to Washington against interfering in nearby territories.

At the same time, it reminds Russia’s allies, including Cuba and Venezuela, that Moscow is on their side.

According to CNN, the warship’s arrival strengthens the ties between Moscow and Havana despite the ongoing war in Ukraine.