Pyongyang has boycotted the nuclear talks since November 2005 to protest US
sanctions imposed on a Macau bank accused of complicity in North Korean
counterfeiting and money-laundering.
The United States and North Korea agreed to discuss the sanctions on the
sidelines of the nuclear talks.
On Wednesday, US Deputy Treasury Secretary Robert Kimmitt said the sanctions
talks would be a continuation of a New York briefing in March where American
officials explained their case to North Korean officials.
The moves to blacklist Macau's Banco Delta Asia are
"not sanctions, they are law-enforcement measures under the laws of the
United States," Kimmitt said in Seoul after meeting with the South's nuclear envoy.
On Tuesday, the United States and South Korea also introduced a possible
complication to the talks when they said they would refuse to treat the North as
a nuclear state.
The US-Chinese talks this week are the third round in a "strategic dialogue"
that began last December. The dialogue was agreed to in 2004 by President Hu
Jintao and his US counterpart, George W. Bush.
Meanwhile, there were signs of disagreements between Seoul and Washington on
how hard to press the North. South Korea has been struggling to balance its
obligations to punish the North under the U.N. sanctions resolution with
concerns that aggravating its volatile neighbor could destabilize the region.
In Tokyo, the US diplomats and Japanese officials agreed
Monday to have all five of the North's negotiating partners meet during an
Asia-Pacific economic conference this month in Vietnam.