South Korean President, Moon Jae-in today said North Korea would be crossing a red line if it put a nuclear warhead on an intercontinental ballistic missile.<br/><br/>Speaking at a news conference to mark his first 100 days in office Moon said Seoul would consider that Pyongyang is crossing a red line if it launches an intercontinental ballistic missile again and weaponises it by putting a nuclear warhead on top of the missile.<br/><br/>However, he said U.S. President Donald Trump has promised to seek Seoul's approval before before taking any military action.<br/><br/>Moon urged North Korea not to make further provocations, saying it would face much tougher sanctions that the impoverished country would be unable to withstand if it persists with its nuclear weapons development.