The U.S. military said on Monday it had staged bombing drills with South Korea, flying a pair of B-1B bombers and F-35 fighter jets over the Korean peninsula, in a show of force against North Korea.
Mattis also confirmed that Washington and Seoul had discussed returning tactical nuclear weapons to South Korea, where support has grown for such a move as a potential response to North Korea's actions.
Defense Secretary James Mattis on Monday revealed he has secret military options to strike North Korea - but he's not ready to reveal them publicly.
"Yes, there are, but I will not go into details", he said bluntly.
The 1950-53 Korean War was one of the deadliest in modern history, killing millions of Koreans, majority civilians, and tens of thousands of United States and Chinese troops, as well as soldiers from other countries who fought under the UN banner.
Any conflict on the Korean peninsula could lead to bloodshed unseen since the 1950-53 Korean War, which took the lives of more than 50,000 Americans and millions of Koreans and ended in an armed truce, not a peace treaty.
On Sept.7, according to an official press release, Mexican President Enrique Peña Nieto issued an executive order instructing all government agencies to comply with new UNSC economic sanctions imposed on North Korea.
"Things are much different between now and when the United States pulled out nuclear weapons from the Korean Peninsula" in 1991, said Song.
South Korean President Moon Jae-in has openly warned the US against doing just that, and has worked to use diplomacy and deterrence to counter Kim.
"We must be willing to do more than to listen to our allies", the USA defense secretary said.
Trump has hinted that any use of lethal force against North Korea would be overwhelming, using phrases like "fire and fury" that evoke images of nuclear war.
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Russian oil major Rosneft will also invest in pipelines to export gas to Turkey and Europe . No prior warning was given and it's unclear how long the military operation will last.
".We all know that basically if North Korea keeps on with this reckless behavior, if the United States has to defend itself or defend its allies in any way, North Korea will be destroyed".
Still, despite heated rhetoric and posturing in the United States and North Korea, there has been no positioning of USA military weaponry to suggest a military conflict is imminent.
Pyongyang has claimed the measures - including a ban on textiles and a cap on oil supplies - will speed up North Korea's nuclear weapons programme. China in turn favors an worldwide response to the problem.
And South Korea and the USA will also conduct a combined missile alert drill joined by Japan between late September and early October.
"You see it as a primary effort of the United Nations General Assembly meetings going on this week in NY", he said.
"We are putting the leader in North Korea in a position to be aware of - [with] the worldwide community voting unanimously twice now in the United Nations Security Council - ... the increasing diplomatic isolation that comes with the economic sanctions", Mattis said.
A group of South Korean lawmakers from the opposition Liberty Party Korea said in a statement Sunday that the US government was cool to the idea during a visit to Washington to meet State Department officials, members of Congress and scholars.
The official, who spoke on condition of anonymity, did not elaborate, but his mention of "enablement" was likely a reference to China.
Mr Mattis also said diplomacy and sanctions were working and putting pressure on Pyongyang.
China has urged the United States to refrain from making threats to North Korea.
Mattis said the US and Japan did not shoot it down because it did not pose a direct threat to either nation.