It is now far stronger and more powerful than ever before.
Between around 3am and 6am east coast time Wednesday, Trump, who is on what appears to be a "working vacation" at his golf club in Bedminster, New Jersey, retweeted Fox and Friends social media posts five times.
Trump followed up on Twitter on Wednesday morning.
She also said the U.S. doesn't have a problem with the North Korean people, "it is the regime itself".
Ironically, much of the modernization was set in motion under President Barack Obama, who was a lifelong opponent of nuclear weapons, negotiated New START and became the first sitting president to visit Hiroshima, site of the world's first nuclear attack by the United States in World War II.
"The DPRK should cease any consideration of actions that would lead to the end of its regime and the destruction of its people", Mattis said in the statement. Another included a video clip of Trump vowing to respond to North Korean threats with "fire and fury".
If Trump's goal with two days of tough talk was to scare North Korea, Kim, the commander, put that idea quickly to rest.
Secretary of State Rex Tillerson authorized the ban following the death of Otto Warmbier, a USA citizen and student who was detained North Korea for 17 months before being released and evacuated home to Ohio.
'Americans should sleep well at night, ' Mr Tillerson said.
North Korea announced a detailed plan on Wednesday to launch a salvo of ballistic missiles toward the U.S. Pacific territory of Guam, a major military hub and home to U.S. bombers.
He downplayed speculation that the threats move the USA closer to a military option.
North Korea, no stranger to bluffing, frequently uses extremely bellicose rhetoric with warnings of military action to keep its adversaries on their heels. Tillerson says nothing he's seen or knows of in the last day dramatically changed the situation.
She dismissed a suggestion that others in the White House weren't fully behind President Trump's vow to meet threats from President Kim Jong Un's regime with "fire and fury" after Secretary of State Rex Tillerson assured Americans they should have "no concerns" and said there was no "imminent threat".
Tillerson spoke to reporters as he flew from Malaysia to Washington, stopping in Guam to refuel.
Murphy's critical response is based on the failure of US diplomacy in the region and on the large number of vacancies at the State Department.