UN Ambassador Susan Rice was relatively tame:
STEPHANOPOULOS: Is the United States prepared to pressure China?
RICE: We're working very closely with China. China shares the same goal that we do, which is a de-nuclearized Korean Peninsula. China also is very proximate, on the border with North Korea, and shares our desire not to see this situation escalate, and to ensure that we can achieve, George, the long-term goal, which is de- nuclearization of the Korean Peninsula through the six-party talk process.
STEPHANOPOULOS: But because China is right on the border of North Korea, they've been reluctant to really pressure North Korea. They're afraid that if you turn the screws too hard on North Korea, the regime is going to collapse and there's going to be chaos.
And is that why they are not going along with tougher sanctions?
RICE: Well, I think they have multiple concerns. They are looking at the large long-term goal of ensuring that we don't have a nuclearized Korean Peninsula. There have been times when we have differed as to the best means of achieving that.
But we are unified with China and others in the six parties towards the goal, George, of ensuring that we roll back this nuclear program that North Korea is pursuing.
STEPHANOPOULOS: But is there any evidence at all that North Korea is going to respond to any of this? They've been steadily adding to their nuclear program, in fits and starts at times, but basically they've been able, over the last eight years or so, to develop a nuclear capability, to develop nuclear warheads, and they seem determined to keep going on that track. RICE: Well, George, it is fits and starts. I mean, there have been steps that have occurred over the last years that have been progress. For example, they did take steps to dismantle the facility at Yongbyon, which was the principal reactor. Read more or watch the video here