The chief U.S. negotiator for talks to persuade North Korea to abandon nuclear weapons is in Beijing. China, which hosts the six-party talks, has joined North Korea in calling for a speedy resumption of the stalled dialogue.
Ambassador Stephen Bosworth arrived in Beijing Wednesday, as part of growing international efforts to end North Korea's nuclear programs.
Just before heading to China Wednesday, Bosworth said he does not expect any speedy breakthroughs on the issue.
"We're not interested in negotiations just for the sake of talking. We want talks that lead to specific and concrete results," he said.
Some of the concrete results he pointed to include improved relations between North and South Korea. He told reporters in Tokyo that Pyongyang also must show what he described as "significant progress towards denuclearization" before Washington would be willing to discuss lifting international sanctions imposed on North Korea last year.
The six-party talks have been stalled since last year, when Pyongyang walked out. Shortly afterward, North Korea carried out a nuclear test.
The talks include the United States, North Korea, China, South Korea, Japan and Russia.
One recent sticking point in relations between Pyongyang and Seoul involves the sinking of a South Korean ship, the Cheonan, in March. An international investigation blames Pyongyang, but the North Korean government denies any responsibility.
Despite the Cheonan sinking, South Korea has moved to ease tensions by offering millions of dollars in humanitarian aid to North Korea, following heavy rains and flooding there.
During a recent visit to China by North Korean leader Kim Jong Il, the two countries said they would like the talks to resume quickly.
Foreign Ministry spokeswoman Jiang Yu reiterated that position this week.
Jiang says the Chinese government is working with all parties to, in her words, "create the conditions for restarting the six party talks."
She says Bosworth will meet with Wu Dawei, China's special representative to the talks.
The U.S. envoy spoke with officials in South Korea and Japan before heading to China, his last stop.