In a statement published by Pyongyang’s official Korean Central News Agency, senior North Korean official Kim Yong Chol said there has been no substantial progress in relations despite warm ties between leader Kim Jong Un and President Donald Trump. He said the persisting hostility means “there can be the exchange of fire at any moment.”

Kim Yong Chol said the Trump administration would be “seriously mistaken” if it ignores an end-of-year deadline set by Kim Jong Un to propose mutually acceptable terms for a deal to salvage nuclear negotiations.

The North issued a similar statement on Thursday that was attributed to veteran diplomat Kim Kye Gwan. He criticized U.S. officials for maintaining “Cold War mentality and ideological prejudice” and urged the United States to act “wisely” through the end of the year.