The rhetoric of both has threatened to escalate an already tense situation that the international community, including North Korea's only diplomatic ally China, has attempted to control by imposing crippling sanctions on Pyongyang's already isolated economy.
The majority of the arsenal is Soviet- or Chinese-built, rusty and aging, according to a 2015 report from the US Department of Defense.
It has been specifically designed for penetrating advanced anti-aircraft defenses.
"At certain sections of the route the Tupolev-95MS crews were accompanied by a pair of F-18 fighters (of the US Air Force), and a pair of F-15, F-4 and F-2A fighters (of the Japanese Air Force)".
On the other hand, the North Korean country is not afraid of starting a war and has increased its nuclear tests.
Mattis said the North engages in "outlaw" behaviour and that the US will never accept a nuclear North.
General Mattis sought to reassure US allies in the region by saying North Korea is outmatched by the firepower and cohesiveness of the decades-old US-South Korean alliance.
"In this day and age of precision bombing and all weather capabilities, (such) North Korean civil exercises either come from ignorance of modern war or just a propaganda campaign to frightening their own people and induce obedience", LTG Chun said.
Pyongyang has at least 700 170-millimeter guns and 240-millimeter multiple-rocket launchers that can reach Seoul, according to a 2012 study by the Nautilus Institute for Security and Sustainability in California.
Mattis met with South Korean Defense Minister Song Young-moo earlier this week when the two attended a conference of Southeast Asian defense chiefs in the Philippines.
In August, Trump warned North Korean leader Kim Jong Un not to make any more threats against the United States.
His view was widely shared in Washington.Like others, Cohen underestimated the resilience of NorthKorea's ruling dynasty that started with Kim Il Sung.
A US military statement confirmed the B-2 mission was conducted to "familiarise aircrew with air bases and operations in different geographic combatant commands, enabling them to maintain a high state of readiness and proficiency".
"I cannot imagine a condition under which the United States will accept North Korea as a nuclear power".
Japanese retail sales are Monday's lone economic release of note in the region, forecast to bounce back with a 0.8 percent advance month-on-month in September on the heels of a 1.6 percent decline in the prior print. Later in the week, China PMIs, Japanese industrial output and CPI readings from South Korea, Indonesia and Thailand are among the Asian economic data highlights.