North Korea’s suspected launch of its most powerful intercontinental ballistic missile (ICBM) failed on Thursday, according to a South Korean government source, as Pyongyang intensified its battery of missile tests against a backdrop of US and South Korean military drills that had been scheduled to end on Friday. However, within hours of the presumed failed test, Washington and Seoul agreed to extend those large-scale exercises to an unknown date, according to a statement from the South Korean Air Force, which said “it was necessary to demonstrate a solid combined defense posture of the bilateral alliance under the current security crisis, heightened by North Korea’s provocations.” The joint exercises, named “Vigilant Storm,” began on Monday and involve 240 aircraft and “thousands of service members” from both countries, according to the US Defense Department. North Korea had objected to those drills in statements issued this week, before it ramped up tensions on the peninsula with a b