US President Donald Trump and his Secretary of State Mike Pompeo have brushed aside North Korean leader Kim Jong-un's demand for Washington to show more flexibility in nuclear talks by year-end.
Asked about Kim's statement last week that he was only interested in meeting Trump again if the US came with the right attitude, Pompeo told reporters the president was "determined to move forward diplomatically."
But Pompeo said Kim had made a commitment to denuclearise and "we collectively need to see that outcome move forward."
Trump and Kim have met twice, in Hanoi in February and Singapore in June, seeming to build personal goodwill but failing to agree on a deal to lift sanctions in exchange for North Korea abandoning its nuclear and missile programs.
The Hanoi talks collapsed after Trump proposed a "big deal" in which sanctions would be lifted if North Korea handed over all its nuclear weapons to the US. He rejected partial denuclearisation steps offered by Kim.
Breaking his silence on the summit in a speech to North Korea's Supreme People's Assembly on Friday, Kim said it was "essential for the US to quit its current calculation method and approach us with a new one."
He said North Korea would "wait for a bold decision from the US with patience till the end of this year," raising the potential for the unresolved North Korea nuclear issue to become a liability for Trump during his 2020 re-election bid.
In a speech in Minnesota, Trump nevertheless maintained an upbeat tone on North Korea, saying the issue was "moving along" with Pyongyang sticking to a freeze in nuclear and missile testing in place since 2017.
He again stressed his "very good relationship" with Kim "who just said the other day he looks forward to more talks."
"Talk is OK. Talk is OK," Trump said adding that he did not want the process to move fast. "It doesn't have to move fast. Right now it's moving along just perfectly. And we have a good relationship, the sanctions are on ... there's a lot of constructive things going on."
On Saturday, Trump said a third summit with Kim "would be good in that we fully understand where we each stand."
Despite Trump's and Pompeo's remarks, US officials have acknowledged that the two sides have failed to agree on a definition of denuclearisation.
And in a year of talks, Pyongyang has given no public indication of willingness to abandon its weapons program unilaterally as Washington has demanded.
Australian Associated Press