BRUSSELS—Russian President Vladimir Putin would be crossing a “very important line” if he were to order the use of nuclear weapons in Ukraine, NATO Secretary-General Jens Stoltenberg warned Thursday, as both the military alliance and Russia are due to hold nuclear exercises in the next few days.
NATO is holding its exercise, dubbed “Steadfast Noon,” next week. The long-planned maneuvers are conducted around the same time every year and run for about one week. They involve fighter jets capable of carrying nuclear warheads, but do not involve any live bombs.