Trump insults make rocket attack 'inevitable': N Korea

North Korea has warned that US President Donald Trump's bellicose remarks against the Asian country and its leader will make the US mainland an "inevitable" target for rocket attacks.

North Korean Foreign Minister Ri Yong-ho's remarks on Saturday in a speech at the United Nations General Assembly came hours after the US flew bomber jets near North Korea.

"Through such a prolonged and arduous struggle, now we are finally only a few steps away from the final gate of completion of the state nuclear force," Ri told the annual gathering of world leaders in New York. Trump responded on Twitter by once again insulting North Korea's leader Kim Jong-un, calling him "little rocket man" and saying him and Ri "won't be around much longer".