SEOUL, South Korea -- The U.S.-South Korean alliance can defend South Korea, Pacific allies and the American homeland from nuclear and missile threats emanating from North Korea, two top American military officials said here yesterday.Marine Corps Gen. Joe Dunford, the chairman of the Joint Chiefs of Staff, and Army Gen. Vincent K. Brooks, the alliance commander in Korea, said the capabilities already in South Korea are enough to defend against a strike from Kim Jong Un, the North Korean dictator.Both men told reporters at the headquarters for Combined Forces Command that U.S. and South Korean officials will continue to examine the threats from North Korea and make adjustments to the force as they are needed and agreed upon.The men spoke after meetings with senior Korean leaders, including President Moon Jae-in, Defense Minister Song Young-moo and Korean Defense Chief Army Gen. Lee Sun-jin. "The message today was the ironclad commitment to the alliance," Dunford said at the press conference.The U.S. and South Korea each want a peaceful solution, he said. "What I would like to see is Kim Jong Un to commit to ceasing the development of nuclear weapons and ceasing the testing of ballistic missiles," Dunford said.The chairman said the men shared some thoughts about the common challenges facing their nations, but focused mostly on North Korea. He said he also spoke to Korean leaders about his trip to China, "and the messages we would be delivering when we met with our Chinese counterparts."The meeting follows passage of a resolution in the United Nations Security Council that imposed severe sanctions on North Korea for its continued efforts to develop intercontinental ballistic missiles and nuclear weapons. The world is uniting against the North Korean threat, and even China -- North Korea's only ally -- voted for the resolution. China announced today that it would implement an import ban tomorrow on North Korean iron ore, lead and coal as part of the sanctions.GUAMIn response to questions about the U.S. response if North Korea were to launch missiles against Guam, Dunford asked reporters to not confuse military action with policy. "What we would do in the event of an attack on Guam -- or missiles being launched towards Guam -- is a decision that will … be made by the president of the United States and he will make that in the context of our alliance," the chairman said. "Our job -- General Brooks and I -- is to make sure our leadership has options available to them to properly respond."The men have two priorities, he explained. The first is to defend against an attack and the second is to ensure the alliance has a decisive response in the event of an attack.But discussions of a preemptive attack are premature, to say the least, Dunford said. The United States is fully committed to the current policy of applying diplomatic and economic pressure to address North Korea's malign intentions. "The military dimension today is directly in support of that diplomatic and economic effort," he said. "We are seeking peaceful resolution to the crisis right now."The chairman stressed that all the decisions being made now and all the discussions the United States is having are in the context of the alliance. "We listen very carefully to Kim Jong Un's rhetoric and we can't afford to be complacent. … We have to take it seriously in regards to our defensive measures, and with regard to the development of military options in the event we are called upon to do that," Dunford said.He added that any changes to the U.S. posture in the region will be made in consultation with the Japanese government -- who are also under threat from North Korea.STRONG AND PREPAREDBrooks said the alliance is strong and is prepared to face the threat from North Korea. There are 28,500 U.S. service members on the peninsula and that number fluctuates from time to time due to exercises and new capabilities. But not enough has been said about the South Korean military and its contributions, the general said. "There are 660,000 South Koreans who are on active duty at any given time in defense of South Korea, and we are their partner, their ally," he said. "We don't defend by ourselves ... We defend one another in an integrated way."The Combined Forces Command is truly a combined command, Brooks said -- U.S. and South Korean forces are integrated in a manner not seen anywhere else in the world. "So I hear the voices not just of the Americans who are here, but the voices of the South Koreans," he said. "[Troops from both nations] tell me that they want to be ready. They want to make sure they can do all they can to be prepared. They want to know if they have reason to be concerned, and in the meantime we tell them to continue their mission, and they do it very, very well every single day."Brooks noted the role played by the combined exercises in which the United States and South Korean forces take part. The annual exercise Ulchi Freedom Guardian begins next week and, he said, as a matter of course it draws condemnation from North Korea. "This is why our exercises are so important -- we have to have a credible deterrent," the general said. "This is why we have military capability that undergirds our diplomatic activities. These threats are serious to us, and thus we have to be prepared."