The US Secretary of State Rex Tillerson said that while diplomacy was preferred “those diplomatic efforts are backed by a strong military option if necessary”.
Mr Tillerson’s chilling warning comes after Donald Trump hit back at Kim Jong-un saying: “I too have a nuclear button, but it is a much bigger and more powerful one than his and my button works.”
The US President’s comment came as a response to the North Korean dictator’s New Year speech where he threatened the US and claimed “a nuclear button is always” on his desk.
The despotic leader also said Pyongyang was open to talks with South Korea, which have now been scheduled for next Tuesday.
But Mr Tillerson has warned that if denuclearisation talks fail with the US and its South Korean ally that “strong military options” are available.
The US Secretary of State said: ”I think the rhetoric that North Korea understands is that while it is our objective, and the President’s been very clear, to achieve a denuclearisation through diplomatic efforts, those diplomatic efforts are backed by a strong military option if necessary.
“That is not the first choice and the President’s been clear that’s not his first choice, but it is important that North Koreans as well as other regional players understand how high the stakes are, in an effort to ensure our diplomatic efforts are fully supported.
“The North Koreans have to understand that the penalties to them will continue and will only grow more severe in terms of sanctions actions and other actions until they do get on a pathway to achieve that objective that the entire world hopes to achieve.”
Mr Tillerson also made clear that complete, verifiable and irreversible denuclearisation will be the aim of any dialogue.
He said: ”We clearly need a signal from North Korea that they understand these talks must lead to that conclusion.
“The pathway of how you get there, that is the nature of a negotiation. There’ll be some give and take to achieve those objectives. So that objective has never changed.”
He also emphasised the US’ international support against North Korea as sanctions have been repeatedly placed on the rogue state by the United Nations and unilaterally by other country.
On Friday North Korea’s main ally China revealed it had tightened trade restrictions with North Korea and banned outbound shipments of steel goods and limited the export of oil products.
Mr Tillerson added: ”I think it is a recognition that the president has demonstrated to the world how high the stakes are. That’s why we must achieve a diplomatic outcome.”
The US Secretary of State also revealed he remained doubtful over a successful outcome from diplomatic talks and denuclearisation of North Korea.
The President’s been very clear, to achieve a denuclearisation through diplomatic efforts, those diplomatic efforts are backed by a strong military option if necessary
“I know some are speculating that this might be their first effort to open a channel, but as you know, we’ve had channels open to North Korea for some time, so they do know how to reach us if and when they’re ready to engage with us as well.”
North Korea’s state media last year announced that Kim Jong-un’s regime will not continue to enhance its nuclear capabilities in 2018.
KCNA said: “The DPRK, an undeniable new strategic state and nuclear power, declares: Do not expect any change in its policy.
“On February 12 the DPRK successfully test-fired the new type strategic weapon system Pukguksong-2, ground-to-ground intermediate-range strategic ballistic rocket.
“The US persistent moves against the DPRK in political, economic, military, diplomatic and all other fields till the end of this year could not stop even a moment the advance of the DPRK confident in the victory of its cause.”The DPRK, as a responsible nuclear weapons state, will lead the trend of history to the only road of independence and justice, weathering all tempests on this planet.”