Warning there is a "limit to our patience," North Korea has called on the United States to change its approach to nuclear talks.
In a statement published Tuesday by the official Korean Central News Agency, a North Korean foreign ministry official said that if Washington doesn't change its approach, the statement signed last year in Singapore would turn out to be a "mere blank sheet of paper."
“The U.S. would be well-advised to change its current method of calculation and respond to our request as soon as possible,” the North Korean statement said. “There is a limit to our patience.”
A February summit in Vietnam between Kim Jong Un and Donald Trump broke down over disagreements on how to match the pace of sanctions relief with steps to dismantle North Korea’s nuclear program.
Since then, there have been no outward signs of progress in the talks.
Citing a single, anonymous source, South Korea’s Choson Ilbo last week reported Kim Hyok Chol, North Korea’s top envoy to the U.S., had been executed after the failed Hanoi summit.
CNN on Tuesday reported the diplomat is still alive but in state custody and under investigation for his role in the summit. It also said that former spymaster Kim Yong Chol’s power has been “almost deprived” since the Hanoi meeting.
Though Trump has repeatedly insisted his relationship with Kim remains positive, it is not clear how much contact the two men have had since the February summit. "I think the Chairman Kim would like to make a deal and I'd like to make a deal with him. I look forward to seeing him at the appropriate time," Trump said Wednesday.
WATCH: Trump Optimistic; North Korea Warns 'Patience Wearing Thin'
White House National Security Adviser John Bolton said in April that Trump sends Kim pictures and letters, and even sent congratulations on the birthday of Kim’s grandfather, Kim Il Sung.
In late May, when the president was visiting Japan, Bolton admitted there was no sign the outreach was working.
“We really have not heard much from North Korea since the Hanoi summit,” he told reporters. Bolton said Stephen Biegun, the Special Representative for North Korea, “is ready at any point to get on a plane and go anywhere to talk to them.”
Kim wants immediate sanctions relief in exchange for steps toward denuclearization. Trump has said he will not ease sanctions until North Korea agrees to give up its entire nuclear program.
North Korea is gradually ramping up pressure on Washington. Last month, it resumed ballistic missile tests for the first time in 17 months.
Kim said last month said he will give the U.S. until the end of the year to change its approach.