"(But) we could be left with no choice but to seek a new way if the USA does not make good on its promises, misjudges our patience, while seeking to force things unilaterally and clinging to sanctions and pressure", he said. "Therefore, we have already declared domestically and internationally and took various actions showing our commitment that we will no further create or test nuclear weapons and will not use or spread them". Noting that neither would be possible under current sanctions, the New York Post speculated Kim is still interested in driving a wedge between the USA and South Korea by making offers that will push Seoul to demand sanctions relief for the North or unilaterally defy the sanctions.
He also said the US and South Korea should no longer carry out joint military exercises - which have been largely halted since the Singapore meeting - calling such drills "a source of tension".
It came after a year of high tensions when the North made rapid progress with its weapons development, carrying out its sixth nuclear test - by far its most powerful to date - and launching rockets capable of reaching the entire U.S. mainland.
Donald Trump said in a Christmas statement that the progress has been made with regards to North Korea, and he is anticipating his next bilateral meeting with North Korean leader.
In the joint declaration, Kim pledged to work towards the complete denuclearization of the Korean Peninsula, while in return, Trump promised to provide certain security guarantees to North Korea.
Duyeon Kim of the Center for American Security told CNN he found Kim's message "confident, normal, sophisticated" and "reminiscent of the feel of the Singapore summit setting" when Kim met with Trump last summer.
Kim renewed his calls for a complete end to joint military drills between South Korea and the USA and demanded that no foreign military strategic assets be brought onto the Korean Peninsula, saying that they are a "source" of tensions in the region.
Kim's speech "expressed his frustration with the lack of progress in negotiations so far", said former South Korean vice unification minister Kim Hyung-seok. "Discussions on reducing or eliminating that arsenal come later", said Mount.More news: Royal 'Fab Four' spotted at Christmas Day service
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The North has dismantled some testing facilities but there are allegations it is continuing its weapons programme.
The North Korean leader is also indirectly demanding his neighbors to the South push the U.S. and U.N Security Council harder to lift sanctions in exchange for the two countries to resume inter-Korean cooperative projects, Cheong said.
Kim used his New Year's speech a year ago to start a newfound diplomatic approach with Seoul and Washington, which led to his meetings with Moon and Trump.
"Up until even last year, he stood and read the New Year's speech in a rather stiff and strong tone", Cheong said.
But while South and North Korea have continued to mend their relations over the past year, denuclearisation negotiations between Pyongyang and Washington appear to have stalled.
Mr Kim and Mr Trump met for the first time in Singapore in June but, despite a great deal of hype, the resulting agreements were vague on how denuclearisation would be achieved. North Korea has broken promises made to the United States to halt is nuclear weapons program on at least six prior occasions.
North Korea's media have slammed the US for clinging to sanctions without honoring its promises to Pyongyang.
But while Kim Jong Un says he wants to continue along the diplomatic path, the clear hint is that without some response from the United States, the rapprochement witnessed previous year may go into reverse. There are views that North Korea wants a quick second summit because it thinks it can win major concessions from Trump that they probably couldn't from lower level USA officials, who are more adamant about the North committing to inspections and verification.