The U.S. and South Korean air forces will conduct over 2,000 sorties during round-the-clock joint exercises this week, simulating situations that could arise in a war with North Korea.

The five-day training kicked off on Monday and will run for 120 hours as part of the allies’ annual Ulchi Freedom Shield (UFS) drills, according to the ROK air force, with the two sides set to practice responding to DPRK cruise missile attacks and other threats.