The military alliance started its annual nuclear exercise "Steadfast Noon" with up to 60 aircraft taking part on Monday.

"Steadfast Noon" will see more than 60 aircraft, including nuclear-capable fighter jets, carry out training flights over western Europe.

This Monday, NATO launches its annual nuclear exercise, “Steadfast Noon,” a large-scale operation involving more than 60 aircraft and 2,000 troops over the course of two weeks. Though no real weapons will be used,

This year's Steadfast Noon exercises will primarily take place over the host countries, Belgium and the Netherlands, with additional flights over Denmark, the United Kingdom, and the North Sea, NATO said.