BERLIN >> Russia sent a pointed reminder on Tuesday that it could use battlefield nuclear weapons in Ukraine, releasing video of its forces beginning exercises to practice their use, two weeks after President Vladimir Putin ordered the provocative drills.

Video released by the Russian Defense Ministry showed a caravan of military vehicles moving down a wooded road, as well as mobile Iskander missile systems — which can deliver conventional or nuclear explosives — getting into position to launch, with their warheads blurred out. The footage also showed a supersonic strategic bomber armed with missiles and an attack aircraft being prepared for takeoff.

In a statement, the Russian Defense Ministry said the exercise, carried out near Ukraine, was aimed at preparing the force for the possibility of using tactical nuclear weapons. The goal is to “unconditionally ensure the territorial integrity and sovereignty of the Russian state in response to provocative statements and threats of individual Western officials,” the ministry said.

Upon announcing the drills this month, the Kremlin suggested the move was a response to comments by President Emmanuel Macron of France, who refused to rule out sending French troops to Ukraine, and David Cameron, Britain’s top diplomat, who said Ukraine could use British weapons to strike inside Russia.

Dmitry Peskov, the Kremlin’s spokesperson, at the time called their comments “unprecedented” and described them as a “completely new round of escalation” that merited a response by Moscow.

The exercises were the clearest warning yet from Russia that it might use nuclear weapons in the course of its war against Ukraine.

“It’s transparently an effort at nuclear coercion,” said Jeffrey Lewis, a nuclear nonproliferation expert at the Middlebury Institute for International Studies. “They’ve even blurred the warhead on the Iskander ballistic missiles, which seems unnecessary but theatrical.”

The possibility of the conflict going nuclear has been there from the start, with Russia trying to use its nuclear arsenal to deter Western nations from aiding Ukraine. The day he launched his invasion more than two years ago, Putin warned nations considering intervening to help Ukraine that they would face “consequences such as you have never seen in your entire history.”

Unlike strategic nuclear weapons, launched from great distances and with the power to obliterate whole cities, tactical nuclear warheads are designed for battlefield use. They are made to be used against limited targets, often from relatively short distances, with yields low enough to limit the destruction to a certain area.

The Russian Defense Ministry said Tuesday that the first stage of the exercise had begun in the Southern Military District, which includes much of southern Russia, in addition to areas of Ukraine that Moscow now occupies.