By Josh Smith and Michelle Nichols SEOUL/UNITED NATIONS (Reuters) -North Korea said on Friday its launch of a big new intercontinental ballistic missile this week was designed to demonstrate the might of its nuclear force and deter any U.S. military moves. The United States responded by saying it would push the U.N. Security Council to “update and strengthen” sanctions on North Korea over its “increasingly dangerous provocations,” a move Pyongyang’s allies China and Russia are likely to oppose. Thursday’s launch was the first full ICBM test by nuclear-armed North Korea since 2017. Flight data …