The letter was delivered directly to US Secretary of State Mike Pompeo and stated that North Korean leader Kim Jong-un’s government felt that the process could not move forward.
“The US is still not ready to meet (North Korean) expectations in terms of taking a step forward to sign a peace treaty,” CNN reported, citing sources.
The 1950-1953 Korean War ended in an armistice rather than a peace treaty, leaving US-led UN forces technically still at war with North Korea.
The North has long made clear that it sees an official end to the state of war as crucial to lowering tensions on the Korean Peninsula.
The United States has been reluctant to declare an end to the Korean War until after North Korea abandons its nuclear weapons program.
The Washington Post reported on Monday that US President Donald Trump called off a visit to North Korea by Pompeo after the latter received a belligerent letter from a senior North Korean official just hours after the trip was announced last week.
CNN reported that the letter was sent by the former head of North Korea’s Intelligence Agency, Kim Yong Chol, but it was not known how it was sent. The Washington Post said North Korea had been increasingly communicating through its UN mission.
CNN reported that the letter also mentioned that if a compromise could not be reached and the nascent talks crumbled, North Korea could resume “nuclear and missile activities.”
On Sunday, North Korea’s state media accused the United States of “double-dealing” and “hatching a criminal plot” but did not mention Pompeo’s canceled visit.