At the ministerial, Ri accused the US of backtracking on a joint accord reached by US President Donald Trump and North Korean leader Kim Jong-un at their historic summit in June.

In particular, he called for "simultaneous actions and phased steps" to implement the agreement on complete denuclearization of the Korean Peninsula in exchange for US security guarantees.

Asked if he was concerned about those remarks, Pompeo reiterated the North Koreans' pledge.

"Foreign minister made very clear their continued commitment to denuclearize," he said, according to a transcript released by the State Department. "Compare the anger, frankly, over years and years, and hatred spewed by the North Koreans. This was -- his comments were different."

Ri took issue with Washington's pressure on the international community to keep sanctions on North Korea until the full dismantlement of its nuclear weapons program. North Korea, he said, has taken steps to honor the deal by halting nuclear and missile testing and removing a major nuclear site.

The US has also appeared to "retreat" from declaring a formal end to the 1950-53 Korean War, Ri said, calling that "a very basic and primary step for providing peace on the Korean Peninsula."

Pompeo refused to go into detail on any US consideration of concessions barring an easing of sanctions.

"I'm not going to comment on the negotiations and what others may have proffered or what we have considered," he said. "Just not appropriate. Wouldn't be fair to them or to us as we try and solve this."(Yonhap)