"The United States would have to take full responsibility if the opportunity for diplomacy disappears in Korean peninsula for [the US] not taking corresponding measures," Choe Son Hui told reporters after meeting Russia officials in Moscow, South Korea’s Yonhap news agency reported on Friday.
Choe, who is a close adviser to North Korean leader Kim Jong-un and a one of Pyongyang's key nuclear negotiators, did not elaborate on the probable implications of Washington's failure to address Pyongyang's expectations, Presstv Reported.
The vice foreign minister added that Pyongyang had "given time and taken steps to build confidence", only to receive a "sense of betrayal" in return.
North Korea, currently under multiple rounds of harsh sanctions by the United Nations and the US over its nuclear and missile programs, put a unilateral halt to its missile and nuclear tests shortly before a diplomatic thaw began between Pyongyang and Seoul in early 2018.
Pyonyang and Seoul have since held numerous negotiations, with Kim and South Korean President Moon Jae-in agreeing to further improve ties and restart stalled business initiatives. US President Donald Trump and Kim have also met three times since.
The talks, however, made little progress, largely due to Washington’s insistence on Pyongyang’s complete denuclearization before US sanctions are lifted, which North Korea rejects.
Pyongyang has also criticized South Korea’s continued military drills with Washington and its purchase of US weapons as being harmful to the diplomatic efforts.
North Korea has consequently rejected American and South Korean calls for talks in the past week.
On Monday, Foreign Ministry adviser Kim Kye-gwan rejected Trump’s offer for further talks with the US as “useless” given that Washington viewed Pyongyang “as an enemy”.
Also on Thursday, North Korea rejected Seoul’s invitation for Kim to attend the Association of Southeast Asian Nations (ASEAN) summit in the South Korean capital, Seoul, next week.
Speaking to Reuters, Leif-Eric Easley, who teaches international studies at Ewha Womans University in Seoul, highlighted that Pyongyang sees little benefit in further negotiations.
"North Korea now considers summits without payment for co-operation as empty diplomacy that merely helps Moon and Trump raise domestic political support," he said.