now, mike pompeo went first, speaking to reporters there in pyongyang right before boarding his aircraft and he struck a very optimistic tone, saying that both sides agreed on the denuclearization of north korea and were committed to that. >> but what's denuclearization? does anybody know? >> that's the key question here, and i think from the u.s. side, they thought they understood what it meant. they thought it meant inspection of north korean nuclear facilities, concrete steps being taken on the front end. north korea very clear that they want this to be kind of a tit for tat. they want to take steps and see matched by the u.s., different areas, things they've long sought. they said in their statement that they were very much against this idea of complete, verifiable, irreversible denuclearization, something that most watchers of north korea thought would be a challenge, but something that the u.s. had kind of implied it was not stepping back from in these talks. >> now, speaking of tit for tat, if you take a 30,000-foot view, over the last week, we've had the united states and china essentially engaging in what could be the very first salvos