SEOUL, Feb. 13 (UPI) -- Kim Yo Jong, the powerful sister of North Korean leader Kim Jong Un, said Friday that Seoul's expression of regret over alleged drone incursions was "sensible," but cautioned that any future flights would trigger a "terrible response." The statement, carried by the state-run Korean Central News Agency, followed comments Tuesday by South Korean Unification Minister Chung Dong-young, who expressed "deep regrets" over alleged drone flights into the North as part of the Lee