North Korea has warned the U.S.,... saying Washington would be "seriously mistaken" to ignore the regime's year-end deadline to break the impasse in denuclearisation talks.<br />The regime also cautioned the U.S. not to exploit the friendship between Donald Trump and Kim Jong-un to slow down the process.<br />Kan Hyeong-woo reports. <br />North Korea is pressuring the U.S. to come up with a different approach in denuclearization talks by the end of the year,... threatening serious consequences if it fails to do so.<br />In a statement released Sunday on the North's state-run Korean Central News Agency,... the Vice Chairman of North Korea's ruling Workers' Party Kim Yong-chol said the U.S. would be "seriously mistaken" to ignore the year-end deadline.<br />He also warned the U.S. against delaying tactics that capitalize on the close relationship between North Korean leader Kim Jong-un and President Donald Trump. <br />Kim Yong-chol did credit their personal ties for keeping Pyeongyang-Washington relations from completely falling apart... due to what he called "hostile acts and wrong habitual practices on the part of the U.S."<br />But he said the two leaders' personal rapport can only accomplish so much, saying no substantial progress has been made otherwise in North Korea-U.S. relations... and QUOTE-"an exchange of fire" could happen at any moment.<br />Kim also criticized Washington's call on North Korea to come up with a new proposal for final, fully-verified denuclearization... during last month's UN General Assembly meeting.<br />He said the U.S. is now reverting back to a hostile policy towards North Korea and it's misjudging the patience and tolerance of the regime.<br />Kim Yong-chol was the regime's former point man in nuclear talks with the U.S.,... but he was replaced by Jang Kum-chol after the breakdown of the Hanoi summit in February. <br />Kan Hyeong-woo, Arirang News. <br />