The United States' commitment to providing South Korea with its "nuclear umbrella" against North Korea's nuclear and missile threats might weaken under the presidency of Donald Trump if he is reelected, a senior South Korean security official said Tuesday. Principal Deputy National Security Adviser Kim Tae-hyo made the projection, citing Trump's well-known perspective of alliances as costs that U.S. allies should pay for more or shoulder a bigger share of. "Trump as candidate can be seen as pursuing transactional benefits in terms of the South Korea-U.S. alliance," Kim said at a forum hosted by the Sejong Institute. "It is not unlikely that he would suggest negotiating defense cost-sharing or the deployment of U.S. strategic assets from a cost perspective," Kim said. Source: Yonhap News Agency