Some experts argue that recognizing North Korea as a nuclear-armed state, something Pyongyang seeks, is a prerequisite for such talks.
North Korea has rejected U.S. calls to return to talks.
Asked if it was time to accept North Korea as a nuclear state, she replied: "Wording aside, we are committed to the denuclearization of the Korean Peninsula.
We do not accept North Korea with that status.
"She was acknowledging, as other officials in other administrations have, that North Korea does have nuclear weapons, but in violation of its commitments under the NPT not to pursue nuclear weapons," he told Reuters.