The US will not relent until it achieves its objective of ensuring the Korean Peninsula is free of nuclear weapons, Vice President Mike Pence has said while visiting Japan.
Campaigning for the South Korean presidential election is under way in the wake of the dismissal of former President Park Geun-hye.
Trump has been pressuring China, North Korea's main benefactor, to help defuse the situation over North Korea's development of atomic weapons and long-range missiles but he has also warned that the USA will settle the issue alone if other countries won't help.
"Thermonuclear war may break out at any moment on the peninsula", Kim In Ryong threatened. "Solve the problem in North Korea".
The North held a show of military might in a parade over the weekend and tested another missile on Sunday, which the Pentagon said blew up nearly immediately after launch.
In a veiled warning to China, Pence added that "our treaty (with Japan) covers all the territory administered by Japan, including the Senkaku Islands" - a disputed archipelago in the East China Sea that is controlled by Japan but claimed by Beijing. Trump doesn't seem to know exactly who the leader of North Korea is - or have any grasp of how long he's been in power.
'We'll be conducting more missile tests on a weekly, monthly and yearly basis, ' Vice Foreign Minister Han Song-Ryol said in an interview with the BBC.
The unannounced trip allowed the vice president, whose father fought in the Korean War, to look at North Korean soldiers from afar and gaze directly across a border marked by razor wire.
It says the meeting will give council members an opportunity to discuss ways to maximize the impact of existing United Nations sanctions "and show their resolve to respond to further provocations with significant new measures".
Mr Pence said recent US military strikes in Syria and Afghanistan have showed that the resolve of US President Donald Trump should not be tested by Kim Jong-Un.
"We're going to abandon the failed policy of strategic patience", Pence said.
Pence has met with Japanese Prime Minister Shinzo Abe.
China wants to cool tempers and would like to see a return to multilateral negotiations with North Korea.
Tensions have escalated over North Korean moves to accelerate its weapons development. Five years later, CBN News obtained satellite imagery showing a plutonium production site still in operation near Yongbyon.
South Korea's acting president, Hwang Kyo-ahn, at a meeting with top officials on Thursday, repeatedly called for the military and security ministries to maintain vigilance. The deployment of the anti-missile system Terminal High Altitude Area Defence (THAAD) by the US in South Korea is progressing fast.