With US Secretary of State Condoleezza Rice en route to Asia to press for strict enforcement of UN sanctions on Pyongyang, US officials want Seoul to help inspect North Korean cargo and re-think a lucrative joint project.
"She's not coming here to tell anyone what to do," said Christopher Hill, the lead US negotiator on North Korea, after talks with South Korean officials ahead of Rice's visit.
But US ambassador Alexander Vershbow said Rice would ask Seoul to take part in ship inspections as part of UN sanctions imposed over the North's October 9 nuclear test.
Both China and South Korea have indicated they do not want to intercept ships from North Korea, concerned about aggravating the Pyongyang regime, which warned of "merciless" action against nations that try to enforce sanctions.
It called the sanctions a "declaration of war."
Hill said he cannot confirm Japanese and US media reports that the North is planning a second test. "Obviously this (any second test) would be another in a series of rather severe provocations on the part of the DPRK (North Korea), another sign that the DPRK doesn't respect the international community, nor does it respect the UN, nor the UN Security Council resolutions," he told reporters on Wednesday.
Hill added: "We remain very committed to the diplomatic track should the North Koreans share that interest."
The United States wants South Korea to join the Proliferation Security Initiative (PSI), a US-led inspection programme aimed at stopping the spread of weapons of mass destruction.
Pyongyang's confirmed nuclear test has deepened US worries that the North, part of President George W. Bush's "axis of evil", will transfer weapons and sensitive technology to anti-US groups and nations.
"There are obligations for sanctions on North Korea, also obligations to inspect certain cargoes," Rice told reporters on her plane.
She will visit Japan, South Korea, China and Russia, starting in Tokyo on Wednesday to meet her Japanese counterpart Taro Aso.
Vershbow said Rice would ask Seoul to join the PSI, Yonhap news agency reported. Seoul's Vice Foreign Minister Lee Kyu-Hyung said: "We take part in some PSI activities and stay away from others."
However, he said Seoul is considering changing the scope of its participation in light of the sanctions.
Vershbow also urged a review of financial deals with the North "to ensure that the purposes of the UN resolution are achieved."
South Korean President Roh Moo-Hyun's "sunshine policy" of engagement with the North, including two cross-border projects that provide cash-poor Pyongyang with tens of millions of dollars annually, is now under fire.
Many South Koreans believe Roh has allowed their money -- through the Kaesong industrial estate and Mount Kumgang tourist project -- to be used to build a nuclear weapon now threatening them from across the border.
Hill said Mount Kumgang "seems to be designed to give more money to the North Korean authorities" but added it was not for him to be advising Seoul.
"I'm sure they are doing a very comprehensive study of all inter-Korean dialogue projects and I'm sure when the South Korean authorities are ready to discuss this, they will do so," he said.
Seoul has indicated it would continue both projects.
But with South Korea dependent on US force to ward off the North -- Seoul is under the US nuclear defence umbrella, and there are 29,500 US troops here -- Washington will have some diplomatic leverage.
Roh is facing a new wave of anger since the nuclear test.
"Many people here are bewildered at the government's move of continuing the engagement policy as if nothing has happened," the Korea Times said in an editorial.
"The North reciprocated with a nuclear test, betraying the South that has offered them astronomical amounts of cash and material assistance," it said.

Copyright AFP (Agence France-Presse), 2006