A fleet of Russian warships has reached Cuban waters ahead of planned military exercises in the Caribbean in what some see as a projection of strength as tensions grow over western support for Ukraine.

Three ships slowly crossed the mouth of Havana Bay accompanied by small boats that guided them through the narrow channel.

The flagship frigate, adorned with the Russian and Cuban flags, was greeted by 21 cannon salutes. Sailors in dress uniform stood in military formation as they approached the island.

A nuclear-powered submarine was expected to arrive behind them.

The US military expects the exercises will involve a handful of Russian ships and support vessels, which may also stop in Venezuela.

Russia is a long-time ally of Venezuela and Cuba, and its warships and aircraft have periodically made forays into the Caribbean.

But this mission comes less than two weeks after US President Joe Biden authorised Ukraine to use US-provided weapons to strike inside Russia to protect Kharkiv, Ukraine’s second-largest city, prompting President Vladimir Putin to suggest his military could respond with “asymmetrical steps” elsewhere in the world.

The Biden administration has described Russia’s Caribbean excursion as a routine naval activity, downplaying characterisations of it as a provocation.

“Most of all, the warships are a reminder to Washington that it is unpleasant when an adversary meddles in your near abroad,” said Benjamin Gedan, director of the Latin America Programme at the Washington-based Wilson Centre think tank, referring to the western involvement in Russia’s war in Ukraine.

“It also reminds Russia’s friends in the region, including US antagonists Cuba and Venezuela, that Moscow is on their side.”

Although the fleet includes a nuclear-powered submarine, a senior US administration official told the Associated Press that the intelligence community has determined no vessel is carrying nuclear weapons.

The official said Russia’s deployments “pose no direct threat to the United States”.

American officials last week said the Russian ships were expected to remain in the region through the summer.

In December 2018, a pair of Russian nuclear-capable Tu-160 strategic bombers visited Venezuela in what the Russian military described as a training mission.

Russia also sent Tu-160s and a missile cruiser to Venezuela in 2008 amid tensions with the US after Russia’s brief war with Georgia. A pair of Tu-160s also visited Venezuela in 2013.

Russian ships have occasionally docked in Havana since 2008, when a group of Russian vessels entered Cuban waters in what state media described as the first such visit in almost two decades.

In 2015, a reconnaissance and communications ship arrived unannounced in Havana a day before the start of discussions between US and Cuban officials on the reopening of diplomatic relations.

A State Department spokesperson told the AP that Russia’s port calls in Cuba are “routine naval visits”, while acknowledging its military exercises “have ratcheted up because of US support to Ukraine and exercise activity in support of our Nato allies”.

On Wednesday, Russian foreign minister Sergei Lavrov hosted his Cuban counterpart, Bruno Rodriguez, for talks in Moscow. Speaking to reporters after the talks, Mr Lavrov thanked the Cuban authorities for their position on Ukraine.

Russian military and defence doctrine holds Latin America and the Caribbean in an important position, with the sphere seen as under US influence acting as a counterweight to Washington’s activities in Europe, said Ryan Berg, director of the Americas Programme at the Washington-based Centre for Strategic and International Studies.

“While this is likely little more than provocation from Moscow, it sends a message about Russia’s ability to project power into the Western Hemisphere with the help of its allies, and it will certainly keep the US military on high alert while they are in theatre,” Mr Berg said.

The timing of this year’s mission may serve Russia’s purposes, but it is also raising questions of whether Venezuela’s government may use it as an opportunity to shore up President Nicolas Maduro’s bid for a third term in the July 28 election.

Venezuela’s chief opposition coalition is threatening the ruling party’s decades-long grip on power, and engineering a crisis built on simmering tensions with Guyana is among the scenarios that analysts believe Mr Maduro’s government could use to delay or cancel the vote.

Voters in Venezuela approved a referendum in December to claim sovereignty over the Essequibo territory, which accounts for two-thirds of Guyana and lies near big offshore oil deposits. Venezuela argues it was stolen when the border was drawn more than a century ago.

Guyana is awaiting a decision regarding Venezuela’s claim from the International Court of Justice, but Mr Maduro’s government does not recognise its authority.

The US supports Guyana in the ongoing dispute and assisted it with surveillance flights late last year when Venezuela had threatened to invade the country. Guyana’s government last month gave permission for the US military to fly two powerful F/A-18F Super Hornet jets over its capital in a demonstration of close co-operation.