North Korea for the second time this year has fired a long-range rocket despite warning from the United Nations and the U.S. State-run television has declared the launch a success as South Korean and Japanese officials confirmed that lift-off took place at 9:51 am (6:21 AM IST). Yonhap News Agency has reported that the three-stage rocket's first stage had separated as scheduled and splashed down in the sea off South Korea's southwest coast. Since the 13-day lift-off window opened, Japan has been on high alert despite a suggestion from Pyongyang that it could delay the launch. Tokyo deployed missile defence systems to intercept and destroy the rocket if it looked set to fall on its territory, with missile batteries in and around Tokyo and in the Okinawan archipelago. Meanwhile, North Korea insists the Unha rocket was meant to put a satellite in orbit. South Korean president Lee Myung-bak convened a meeting of national security officials and ministers soon after the launch and a similar meeting was held in Tokyo.