NATO will launch its annual nuclear exercise Steadfast Noon next week, alliance chief Mark Rutte said Friday, as tensions with Russia have risen after a series of air incursions by Moscow.

In a video posted online, Rutte stressed that the two-week drill, starting on Monday, was “regular” and NATO stated it is not linked directly to the Kremlin’s latest actions.

Rutte emphasized the importance of the exercise for maintaining the alliance’s defense capabilities.

He explained the necessity of the drill, saying: “We need to do this because it helps us to make sure that our nuclear deterrent remains as credible, and as safe, and as secure, and as effective as possible.”

He further highlighted the strategic message being sent to potential foes: “It also sends a clear signal to any potential adversary that we will and can protect and defend all allies against all threats.”

According to NATO officials, the exercise—which does not involve live nuclear weapons—will feature about 70 aircraft and 2,000 personnel from 13 member countries. Operations will be conducted from airbases in the Netherlands, Belgium, Britain, and Denmark, with much of the activity centered around the North Sea region.

The war game comes after a series of mysterious drones have disrupted airports and been seen at military sites in a string of NATO countries, including Denmark. US Colonel Daniel Bunch, chief of NATO’s nuclear operations, commented on the drone activity, stating: “Drones are not a new threat to us. Drones are something we understand.”

He acknowledged the heightened surveillance required due to recent events, adding: “The more frequent incursions are obviously something we’re keeping an eye on.”

The exercise is the latest to be held by the alliance as the Kremlin has ramped up its nuclear rhetoric since the start of its all-out war in Ukraine in 2022.

Jim Stokes, NATO’s director of nuclear policy, stated the alliance’s assessment of Russia’s current nuclear stance, saying: “Allies haven’t seen any change in Russia’s nuclear posture.”

He also confirmed that monitoring efforts would continue: “We will, of course, continue to monitor on a regular basis all the Russian nuclear rhetoric, which happens quite often, and the use of dual-capable missiles in Ukraine.”