"(Our) efforts ... are trying to get the North to ... live up to its international obligations," State Department spokesman Robert Wood said Tuesday.
The U.S. delegation, led by Deputy Secretary of State James Steinberg, will be in South Korea through Thursday, then travel to Beijing Friday. A trip to Moscow couldn't be arranged, "but we fully intend to consult with the Russians over the coming days on this issue," he said.
The U.N. Security Council resolution responding to Pyongyang's actions was moving forward, Wood said.
"I think we've seen some progress with regard to the resolution, but there's a lot of work to do," he said. "This is clearly going to take some time. But ... there's a unity of purpose here to hold the North accountable for the bellicose actions and threats that it has made over the last several weeks, months."
Wood said he couldn't confirm reports that North Korean leader Kim Jong-Il signaled his intent to anoint his third son to succeed,.
"We don't really have a good sense as to what's going on inside the country with regard to the -- you know, any possible transition," Wood said.
The spokesman said no sign has been given that North Korea planned to resume denuclearization talks, despite published reports.