A group of US bombers and military jets have flown just off North Korea's coast in a show of force.
The Pentagon said B-1B bombers from Guam and F-15 fighter escorts from Okinawa in Japan flew the mission in international airspace over the waters east of North Korea.
The flights come as both countries engage in a fresh war of words over North Korea's nuclear program, with the rogue state's foreign minister threatening attacks on the US mainland in a speech to the UN.
US Department of Defense spokeswoman said the flyover was intended to underscore "the seriousness with which we take (North Korea‘s) reckless behavior"..
Her statement said the flights are a "demonstration of US resolve and a clear message" that President Donald Trump "has many military options to defeat any threat".
"We are prepared to use the full range of military capabilities to defend the US homeland and our allies," Ms White said.
The move will further increase tensions on the Korean peninsula amid a growing nuclear crisis.
It comes as isolated Pyongyang faced a fresh round of sanctions after refusing to give up its nuclear programme and carried out fresh tests in recent weeks.
Experts say that leader Kim Jong-un is well on the way to developing the technology for a viable nuclear arsenal.
Mr Trump has repeatedly warned that he will not hesitate to turn to military responses if need be.
The president continued his war of words on Twitter with North Korea on Saturday night.
He tweeted: "Just heard Foreign Minister of North Korea speak at U.N. If he echoes thoughts of Little Rocket Man, they won't be around much longer!"
Earlier North Korea's foreign minister threatened a missile attack on the US mainland over Mr Trump's rhetoric.
Foreign Minister Ri Yong-ho addressed the UN General Assembly on behalf of Kim Jong-un, and said Mr Trump's insults makes "our rocket's visit to the entire US mainland inevitable all the more".
Mr Ri described Mr Trump as "a mentally deranged person full of megalomania" who is holding "the nuclear button", and said "Trump himself is on a suicide mission".
"In case innocent lives of the US are lost because of this suicide attack, Trump will be held totally responsible," Mr Ri said.
"Our national nuclear force is, to all intents and purposes, a war deterrent for putting an end to nuclear threat of the US and for preventing its military invasion, and our ultimate goal is to establish the balance of power with the US."
Mr Trump mocked Kim as a "rocket man" on a "suicide mission" during a combative speech at the UN General Assembly on Tuesday.
In recent months, North Korea has launched a pair of intercontinental missiles believed capable of striking the continental United States and another pair that soared over Japanese territory.
Earlier this month, North Korea conducted its most powerful nuclear test to date, drawing stiffer UN sanctions.