Donald Trump
Donald Trump Reuters

U.S. President Donald Trump on Tuesday warned North Korea that a military option would be "devastating" for Pyongyang, but said the use of force was not Washington's first option to deal with the country's ballistic and nuclear weapons program.

"We are totally prepared for the second option, not a preferred option," Trump said at a White House news conference, referring to military force, as quoted by Reuters.

"But,” he added, “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’s comments followed recent tensions between the United States and North Korea, which increased after Pyongyang’s latest tests of a ballistic missile and what it claimed was a hydrogen bomb.

Last week, in his speech before the UN General Assembly, Trump nicknamed North Korean leader Kim Jong Un "Rocket Man", and said he "is on suicide mission for himself and for his regime."

"No nation on earth has an interest in seeing this band of criminals arming itself with nuclear weapons and missiles," Trump said. "It is time for North Korea to realize that de-nuclearization is its only acceptable future."

In response, North Korean's foreign minister said Trump had made an "irreversible mistake" and threatened the "entire U.S. mainland" with missiles.

Trump fired back at the minister, Ri Yong Ho, tweeting, “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!”

On Monday, Ri said Trump’s speech to the United Nations last week and his subsequent tweets were a “declaration of war.”

White House press secretary Sarah Huckabee Sanders later dismissed the claims that the U.S. was declaring war on North Korea.

“We’ve not declared war on North Korea and frankly the suggestion of that is absurd,” she stressed.

Despite the increased tension, the United States has not detected any change in North Korea's military posture reflecting an increased threat, the top U.S. military officer said on Tuesday, according to Reuters.

The assessment by Marine Corps General Joseph Dunford, chairman of the U.S. Joint Chiefs of Staff, about Pyongyang's military stance was in contrast to a South Korean lawmaker who said Pyongyang had boosted defenses on its east coast.

"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," Dunford was quoted as having told a Senate Armed Services Committee hearing on his reappointment to his post.

In terms of a sense of urgency, "North Korea certainly poses the greatest threat today," Dunford testified.

Dunford said Pyongyang will have a nuclear-capable intercontinental ballistic missile "soon," and it was only a matter of a "very short time".

"We clearly have postured our forces to respond in the event of a provocation or a conflict," the general said, adding that the United States has taken "all proper measures to protect our allies" including South Korean and Japan.