Reclusive North Korea has made "qualitative" improvement in its nuclear and missile warfare capabilities, the US has said. US Deputy Secretary of State Antony Blinken said on Thursday the series of nuclear and ballistic missile tests Pyongyang conducted last year has made it all the more necessary to bring Kim Jong Un back to disarmament talks.
"Even a so-called failure is progress because ... they apply what they have learned to their technology and to the next test. And in our assessment, we have a qualitative improvement in their capabilities in the past year as a result of this unprecedented level of activity," Blinken said, according to Reuters.
The US official said in a joint news conference with senior Japanese and South Korean officials that Pyongyang conducted 24 missile tests and two nuclear tests last year.
Blinken said the US, Japan and South Korea should put up a concerted effort to stem the progress North Korea makes in nuclear and ballistic missile weaponry.
In November, Seoul and Tokyo sunk differences over the past conflicts and agreed a landmark deal to share military intelligence in the face of advancing threat from common foe - rogue nation North Korea.
Pentagon said in November it would deploy the Terminal High Altitude Area Defense (THAAD) missile defense system in South Korea as quickly as possible.
The aerial defence system is of huge strategic importance to South Korea and ally US in the face of the ballistic missile programme North Korea pursues on top if the recent advancements it made in developing nuclear arsenal.
Blinken added that beyond the defence partnership it was necessary to pile pressure on Pyongyang."At the same time, it's absolutely vitally important that we exercise sustained, comprehensive pressure on North Korea to get it to stop these programs, to come back to the negotiating table, and to engage in good faith on denuclearization," he said.
The statement follows President-elect Donald Trump's statement that the nuclear ICBM planned by Kim Jong un 'won't happen.'
However, it was not clear how the US can effectively block Pyongyang from conducting advanced ICBM tests. Washington will either have to take military action or get back to the negotiation table with Pyongyang.