A U.S. missile defense system that's now being installed in South Korea will be operational "in the coming days," says Adm. Harry Harris, commander of the U.S. Pacific Command.President Trump and Defense Secretary James Mattis have said all options are on the table to counter what Harris called "the reckless North Korean regime" in his testimony Wednesday before the House Armed Services Committee. But Harris also stated, "We want to bring Kim Jong Un to his senses, not to his knees."Hours before the admiral spoke to members of Congress, parts of the Terminal High Altitude Area Defense missile system, or THAAD, began the trip to their deployment site in a rural part of South Korea."The overnight, unannounced operation came just six days after U.S. Forces Korea (USFK) secured the land in Seongju, North Gyeongsang Province, from the South Korean government," the Yonhap News Agency reports.Large components of the U.S. THAAD system began landing in South Korea early last month, under an agreement that was reached last July.Wednesday's convoy of trucks and equipment included some 20 trucks, the Korea Herald reports, adding, "Although covered by plastic boxes and wrapping, they were believed to include a radar, launchers, interceptors, a fire control and communications unit, a power generator and a cooler."Harris testified ahead of an unusual meeting at the White House on Wednesday, when all 100 U.S. senators are expected to attend a classified briefing on North Korea.China has opposed the deployment, saying the system's radar could provide a new way to spy on its military and that THAAD missiles could undercut China's nuclear deterrent. The country has also warned of an arms race between defensive and offensive weapons on the Korean Peninsula.The U.S. says the THAAD system is not an offensive weapon — a point that Adm. Harris reiterated on Capitol Hill on Wednesday."This system is a defensive system that will help protect South Korea from ballistic missile attacks from North Korea," Harris told the House committee during Wednesday's public hearing. "It is a purely defensive system," he added, saying that the THAAD components are "aimed north" — not at China to the west.Harris said that he takes Kim Jong Un at his word when he threatens U.S. targets. The leader has previously spoken of striking U.S. cities, and this week, North Korea threatened to sink the USS Carl Vinson aircraft carrier."I believe that we have to look at North Korea as if Kim Jong Un will do what he says," Harris told the panel, while acknowledging that for now, at least, there's a "capability gap" between what the North Korean leader has threatened and what his military could achieve.But when that gap is closed, Harris also said, it would represent an "inflection point, and we're going to have to deal with that, I believe."In South Korea, the deployment has stirred a mix of reactions, including protests and clashes with police Wednesday."South Korean television showed images of demonstrators in rural Seongju county, about 155 miles south of the capital, hurling water bottles at trucks carrying parts of the THAAD system," reporter Jason Strother tells NPR from Seoul. "Reports say protesters tried to block its delivery to a golf course that's being converted into a base." Copyright 2017 NPR. To see more, visit http://www.npr.org/.