The fleet of B-1B Lancer bombers was escorted by the F-15C fighter jets over worldwide waters on Saturday.
North Korea's weapons program is a grave threat to the Asia-Pacific region and the entire worldwide community.
North Korea said on Saturday that firing its rockets at the US mainland was "inevitable" after US President Donald Trump called Pyongyang's leader "rocket man", in a further escalation of rhetoric between the two leaders.
The foreign minister said Trump may not realize what he 'uttered from his mouth, but we will make sure that he bears consequences far beyond his words'.
Trump and Kim have been trading insults and threats. over Pyongyang's nuclear ambitions and each have threatened military action.
On Friday, Donald Trump called the North Korean leader Kim Jong Un a "madman", a day after which Kim dubbed him a "mentally deranged USA dotard" who would face the "highest level of hard-line countermeasure in history".
The aircraft flew over worldwide airspace, but it was "the farthest north of the Demilitarized Zone any USA fighter or bomber aircraft have flown off North Korea's coast in the 21st century", chief Pentagon spokesperson Dana W. White said in a statement.
China's Earthquake Administration said the quake was not a nuclear explosion and had the characteristics of a natural tremor.
It does raise many questions, including how would the North undertake such a nuclear test, what risks might it pose to Japan and how would the US respond? The country said that they will also ban imports of textiles from North Korea. "So as of now, we are categorizing this as a natural quake".
The air patrolling started after a series of earthquakes in North Korea sparked fears that the country may have conducted another nuclear weapons test.