In a diplomatic win for the USA, the measures were approved unanimously - including by Russian Federation and China, the North's sole major ally, according to AFP.
North Korea successfully tested an intercontinental ballistic missile last month for the first time, and US intelligence agencies assess that Pyongyang is capable of producing a compact nuclear warhead and putting it atop a long-range missile.
Mattis said the tragedy of war is well-known and "it doesn't need another characterization beyond the fact that it would be catastrophic".
It called former President Barack Obama a monkey and ex-South Korean President Park Geun-hye a prostitute. "The Secretary General welcomes all initiatives that will help deescalate tensions and welcomes a return to diplomacy".
Trump also says the nation's nuclear arsenal is in "in tip-top shape" and getting stronger. That's a Nuclear Posture Review that will set the administration's nuclear policy, per WaPo, after which modernization efforts would take years. His comments punctuate President Donald Trump's warning that North Korea will be met with "fire and fury" if it threatens the U.S.
Pentagon Hopes for Diplomatic Solution on N. Korea, But Has Military Options
Meanwhile, France is urging all sides "to act responsibly and to de-escalate" tensions over North Korea's nuclear ambitions. An attack would require more military assets than the US now has stationed in the Korean peninsula and east Asia.
Trump is also warning about the dangers of nuclear weapons, saying he'd like to "de-nuke the world".
The Northern Viper drills are one of the scheduled exercises that Japan's Self Defence Forces conducts regularly with their US counterparts and are not a response to the latest tensions.
The announcement Thursday warned that the North is preparing a plan to fire four of its Hwasong-12 missiles over Japan and into waters around the tiny island, which hosts 7,000 USA military personnel on two main bases and has a population of 160,000.
Meanwhile North Korea's state-run KCNA news agency said its army would complete plans in mid-August to fire four intermediate-range missiles over Japan to land near Guam.
'His view and the view of the administration is that the way to resolve the situation with North Korea.is through these economic sanctions.
The United States and South Korea remain technically still at war with North Korea after the 1950-53 Korean conflict ended with a truce, not a peace treaty.