The North Korean leader made the grave warning during his New Year address
North Korea's leader has used his New Year message to warn the US that he has a "nuclear button" on his desk - which is always in reach.
In his address, Kim Jong Un said his country's weapons are now a reality and not just a threat.
He used the message to warn the US that the country is now in range of his nuclear warheads.
He also proclaimed that his country achieved the historic feat of "completing" its nuclear forces in 2017.
Kim Jong Un also says expanding his arsenal is now a priority.
"This is reality not a threat. This year we should focus on mass-producing nuclear warheads and ballistic missiles for operational deployment".