The Pentagon has said that US bombers have flown close to North Korea’s east coast to demonstrate the military options available to defeat any threat.
It said the flight was the farthest north of the demilitarized zone (DMZ) between the two Koreas that any US fighter jet or bomber had flown in the 21st Century.
Tensions have risen recently over North Korea’s nuclear program.
At the UN, North Korea’s foreign minister Ri Yong-ho said President Donald Trump was on a “suicide mission”.
Ri Yong-ho’s comments to the General Assembly mimicked President Trump’s remarks at the UN on September 20, when he called North Korean leader Kim Jong-un a “rocket man on a suicide mission”.
The North Korean foreign minister added that “insults” by President Trump – who was, he said, “mentally deranged and full of megalomania” – were an “irreversible mistake making it inevitable” that North Korean rockets would hit the US mainland.
President Trump, the foreign minister said, would “pay dearly” for his speech, in which he also said he would “totally destroy” North Korea if the US was forced to defend itself or its allies.
Donald Trump responded to the speech on Twitter by saying Ri Yong-ho and Kim Jong-un “won’t be around much longer” if they continue their rhetoric.
Shortly before his address, the Pentagon announced that the show of force underscored “the seriousness” with which the US took North Korea’s “reckless” behavior, calling the country’s weapons program a “grave threat”.
“This mission is a demonstration of US resolve and a clear message that the president has many military options to defeat any threat,” the Pentagon said in a statement.
“We are prepared to use the full range of military capabilities to defend the US homeland and our allies.”
US Air Force B-1B Lancer bombers from Guam, escorted by Air Force F-15C Eagle fighters from Okinawa, Japan, flew in international airspace, the Pentagon added.
The flight follows a week of heated rhetoric between the leaders of both countries – after President Trump’s comments, Kim Jong-un called him “mentally deranged” and “a dotard”.
Ri Yong-ho did not comment on the Pentagon’s announcement.
North Korea has refused to stop its missile and nuclear tests, despite successive rounds of UN sanctions. The North Korean leaders say nuclear capabilities are its only deterrent against an outside world seeking to destroy it.
After North Korea’s latest and most powerful nuclear test earlier this month, the UN Security Council approved new sanctions on the country.
However, speaking at the UN, Ri Yong-ho repeated that the restrictions would not make the country stop its nuclear development.
Meanwhile, a 3.4-magnitude tremor was detected near North Korea’s nuclear test site on September 23, but experts believe it was a natural earthquake.
The earthquake was recorded at a depth of 0km in North Hamgyong province, home to the Punggye-ri site, South Korea’s meteorological agency said.
The US Geological Survey (USGS) also said it occurred in the nuclear test area, but added that its seismologists assessed it as having a depth of 5km.
South Korea said no specific sound waves generated by artificial earthquakes were detected.
China’s Earthquake Administration said the quake was not a nuclear explosion and had the characteristics of a natural tremor. The agency had initially said it was a “suspected explosion”.