In the latest addition to a series of threats made against North Korea, US President Donald Trump said the country would face "devastating" consequences if Washington is forced to take military action against the rogue regime. A military attack was not his preferred option, but the US was well prepared to carry out one, he warned.

The war of words between the US and North Korea has been rapidly escalating with both sides threatening to attack each other if things spiral out of control. Trump's latest warning also comes shortly after it was reported that North Korea was seen moving its warplanes and boosting its coastal defence system in response to the recent flight of American bombers.

Speaking at a press conference in Washington along with Spanish Prime Minister Mariano Rajoy, the American leader promised to fix the North Korea "mess".

"We are totally prepared for the second option [military action], not a preferred option. But if we take that option, it will be devastating, I can tell you that, devastating for North Korea. That's called the military option. If we have to take it, we will," Trump said in the White House.

He squarely blamed the Kim Jong-un regime for worsening the situation in the Korean peninsula and "acting very badly". Insisting that the Trump administration should not be accused of increasing tensions, Trump added: "We're replying to those things, but it is a reply. It is not an original statement, it is a reply."

While there is a sharp change in the political posture, little recalibration has taken place in North Korea's military posture, US officials say. Though satellite images showed a small number of North Korean military aircraft moving to the east coast, those are not seen as an immediate threat, US officials who wished to remain anonymous told multiple media outlets.

"While the political space is clearly very charged right now, we haven't seen a change in the posture of North Korean forces, and we watch that very closely," Marine Corps General Joseph Dunford, chairman of the US Joint Chiefs of Staff, told a Senate hearing following his reappointment.

Donald Trump and North Korea
US President Donald Trump speaks during a press conference in the Rose Garden at the White House in Washington Joshua Roberts/Reuters