SEOUL - North Korea has been moving airplanes and boosting defences on its east coast after the United States dispatched B-1B bombers to the Korean peninsula over the weekend, South Korea's Yonhap News Agency reported on Tuesday (Sept 26), citing the country's spy agency.
The US appeared to have disclosed the flight route of the bombers intentionally because North Korea seemed to be unaware, the report said.
South Korea's National Intelligence Service was unable to confirm the report immediately.
North Korea's Foreign Minister Ri Yong Ho said on Monday that US President Donald Trump had declared war on North Korea and that Pyongyang reserved the right to take countermeasures, including shooting down US bombers even if they are not in its air space.
He said a Twitter message by Trump on Saturday in which the president warned that the minister and North Korean leader Kim Jong Un "won't be around much longer" if they acted on their threats amounted to a declaration of war.
But White House spokesman Sarah Sanders on Monday denied the United States had declared war, calling the suggestion "absurd".
Speaking earlier in New York, where he had been attending the annual UN General Assembly, Ri told reporters: "The whole world should clearly remember it was the US who first declared war on our country."
"Since the United States declared war on our country, we will have every right to make countermeasures, including the right to shoot down United States strategic bombers even when they are not inside the airspace border of our country.
"The question of who won't be around much longer will be answered then," Ri added.