SEOUL: The South Korean and United States militaries began massive live-fire drills near the border with North Korea on Thursday, despite Pyongyang warning it won't tolerate what it calls such a hostile invasion rehearsal on its doorstep.

The drills, the first of the allies' five rounds of firing exercises until mid-June, marked 70 years since the establishment of the military alliance between Seoul and Washington. North Korea has typically reacted to such major South Korean-US exercises with missile and other weapons tests.