Harris said he did not publicly describe “tripwires in advance” - what sort of red line North Korea would have to cross for Washington to take military action. “These exercises are very important,” Gen. Brooks said on the ongoing joint military drills. “We have had the responsibility of providing military options to our national leaders, and exercises are a way of making sure that the option is a ready option, a capable option. And that’s what really underpins deterrence. So in our view, we have to continue to exercise until we have a reason not to.” He continued, “That may cause some noise form North Korea. That’s what we routinely expect. But it doesn’t stop us in our resolve to be as ready as possible and leave the greatest number of options.” Brooks also addressed North Korea’s intercontinental ballistic missiles (ICBM) threat and said, “We have seen through demonstrated ability that there is a rapidly developing capability in North Korea; they’re learning quickly, and they’ve stated what they’re after.” He continued, “As a military man, I take them at their word and have to be prepared to counter that if possible and to ensure that it doesn’t happen in the first place if we can - that’s the credible deterrence that we spoke about earlier, while we are giving diplomatic actions and economic actions a chance to be successful.” Brooks said that whether North Korea has mastered the technology to miniaturize a nuclear warhead and place it on an ICBM is “frankly a bit academic ... Their expressed intent is what I operate off of.” Harris stressed a similar message in a meeting with South Korean Minister of Foreign Affairs Kang Kyung-wha the same day, saying, “Diplomacy should always be the main battery,” supported by military defense. A bipartisan, bicameral U.S. congressional delegation led by Sen. Edward J. Markey of Massachusetts, the senior Democrat on the U.S. Foreign Relations Committee’s East Asia