A senior U.S. envoy has arrived in South Korea, saying that United Nations sanctions against North Korea must be enforced so Pyongyang pays a price for its nuclear test. The visit comes as governments in the region examine new signs that Pyongyang is preparing a second nuclear weapons test.
Assistant U.S. Secretary of State Christopher Hill says North Korea's neighbors must help enforce the U.N. resolution punishing Pyongyang for its nuclear test.
"To make sure we have done all we can to impede North Korea's import or export of nuclear materials - to really make it clear that North Korea will pay a very, very high price for this sort of reckless behavior," Hill said.
The measure calls for inspections of North Korean cargo for banned weapons parts. China and South Korea, however, are reluctant to interdict North Korean ships for fear of igniting a conflict.
Earlier Tuesday, officials in Tokyo and Seoul said they are assessing intelligence that Pyongyang might explode a second nuclear device, but gave not details on the information.
Later this week, U.S. Secretary of State Condoleezza Rice visits China, South Korea and Japan to discuss ways to persuade Pyongyang to give up its nuclear program.