(LEAD) U.S. says still ‘monitoring the situation’ By Lee Chi-dong WASHINGTON, Dec. 11 (Yonhap) — The U.S. government has ‘noted’ North Korea’s multistage rocket launch and it is preparing for a formal response, an official said Tuesday.’We have noted the launch and we are monitoring the situation,’ a U.S. administration official told Yonhap News Agency,
