Mr Trump appeared to threaten regime change over the weekend, tweeting to say that the country's foreign minister "won't be around much longer" if he continued to echo the thoughts of North Korean leader Kim Jong-un.
Foreign Minister Ri Yong-ho responded in a press conference, saying: "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," he added.
The Foreign Minister went on to say that "the question of who won't be around much longer will be answered then". He added that "all options will be on the operations table" of the North Korean regime.
The comments echoed the Trump administration's warnings that "all options remain on the table" in dealing with North Korea's burgeoning nuclear programme. The regime has reportedly developed missiles capable of reaching the US homeland, and conducted its sixth-ever nuclear test earlier this month. The country has repeatedly threatened to use its nuclear weapons on the US if provoked.
Mr Trump has responded to the growing threat my escalating his rhetoric against North Korea, at one point threatening to send "fire and fury" to the country if the threats did not cease. In his speech to the United Nations last week, Mr Trump threatened to "totally destroy" North Korea, and referred to Mr Jong-un as "Rocket Man".
Mr Ri responded by saying that targeting the United States mainland with its rockets was now inevitable.
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!— Donald J. Trump (@realDonaldTrump) September 24, 2017
Afterwards, Mr Trump took to twitter to say: "Just heard Foreign Minister of North Korea speak at UN If he echoes thoughts of Little Rocket Man, they won't be around much longer!"
Mr Ri had also called the US President "a mentally deranged person full of megalomania and complacency" who was trying to turn the UN into a "gangsters' nest."