Marines walk by a TV screen showing the live broadcast of South Korean President Moon Jae In's press conference in Seoul. Photo / AP
North Korea would be "crossing a red line" if it put a nuclear warhead on an intercontinental ballistic missile, South Korea's President says, but the US has promised to seek Seoul's approval before taking any military action.
North Korea's rapid progress in developing nuclear weapons and missiles capable of reaching
the US mainland has fuelled a surge in tensions in recent days.
Pyongyang threatened to fire missiles towards the Pacific island of Guam and President Donald Trump warned it would face "fire and fury" if it threatened the US.
"I would consider that North Korea 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," South Korean President Moon Jae In said at a news conference marking his first 100 days in office.
Moon has repeatedly urged North Korea not to "cross the red line" but had not previously elaborated what that would constitute.
