Secretary of Defense James Mattis issued a strong warning to North Korea Monday: "If they shoot at the United States, I'm assuming they've hit the United States. ... If they do that, then it's game on."
"You don't shoot at people in this world unless you want to bear the consequences," Mattis told reporters at the Pentagon.
Soon after Mattis issued his warning, state-run North Korean media outlet KCNA reported that North Korean leader Kim Jong Un had inspected his military's plan to launch missiles at Guam and discussed the possibility of a strike with his top commanders.
"He said that if the planned fire of power demonstration is carried out as the US is going more reckless, it will be the most delightful historic moment when the Hwasong artillerymen will wring the windpipes of the Yankees and point daggers at their necks, underlining the need to be always ready for launching to go into action anytime once our Party decides," the report said.
Mattis said that the US military would be able to determine "within moments" after launch whether or not a North Korean missile was headed for US territory, including Guam. He later added that the US would "take it out" if the missile was determined to be headed for any US territory.
But he also made clear that while the military was poised to protect Guam from the North Korean military threat, a declaration of war was a decision that remains with President Donald Trump and Congress.
"War is up to the President, perhaps up to the Congress, the bottom line is we will defend the country from an attack, for us that's war, that's a wartime situation," he said.
"We will defend the country from any attack, at any time, from any quarter. Yes, that means for a lot of young troops they're going to be in a wartime situation, welcome to reality. But it's not declaring war, it's not that I'm over here Dr. Strangelove doing things like that," he added.
President Trump is due to discuss the crisis with Japanese Prime Minister Abe in a phone call later Monday Washington time.
Mattis' warning comes as a senior US defense official tells CNN that American spy satellites have observed a mobile missile launcher capable of launching an intermediate range ballistic missile being moved in a way that leads the US military to believe preparations are being made for a possible intermediate ballistic launch.
The official cautioned that at this point it's not believed to be directly related to the threat issued by North Korea last week to strike the waters near Guam. However, the official did acknowledge that given typical North Korean missile launch cycles, the recent movement does suggest the regime could be readying for a potential launch of a single missile as soon as in 24 to 48 hours if there has been a decision to proceed with a launch.
Several US officials continue to tell CNN that North Korea often moves missiles and launch equipment around, but that such movements do not necessarily mean there has been a decision to conduct an imminent launch.
The official would not say if there was a missile on the launcher at this time.
On Friday, CNN reported that US spy satellites had observed increased activity at the Chamjin missile factory, according to US defense officials. One US defense official told CNN that US intelligence has assessed that a "probable ballistic missile" was being readied for shipment based on the activity observed. North Korea monitoring project 38 North reports that the Chamjin factory produces many of the medium, intermediate, and intercontinental ballistic missiles used by the regime.
The US and South Korea will start their Ulchi-Freedom Guardian joint military exercises next week. The drills antagonize the North Koreans, as Pyongyang believes they are preparations for an invasion. Seoul and Washington say the exercises are defensive in nature.