Despite US Secretary of State Rex Tillerson's offer on Tuesday to start talks with North Korea without pre-conditions, State Department spokeswoman Heather Nauert said there would first have to be a "period of calm" in which Pyongyang suspends testing before any negotiations could begin.
Tillerson, in a speech to a Washington think tank on Tuesday, did not explicitly establish such a freeze as a requirement that North Korea must meet ahead of talks.
Nauert, speaking at the State Department's daily briefing, insisted that Tillerson was not establishing new policy in his speech, even though he appeared to back away from a key US demand that Pyongyang must first accept that any negotiations would have to be about giving up its nuclear arsenal.