South Korea has taken its first steps to enforce United Nations sanctions against North Korea for its recent nuclear test, including the banning of key North Korean officials from the country.
South Korean Unification Minister Lee Jong-seok, announcing the sanctions Thursday, said the travel ban covers North Korean officials linked to the country's nuclear programs.
Lee said South Korea is also increasing inspections of North Korean ships suspected of carrying weapons and other banned materials.
Just a day earlier, Pyongyang had threatened retaliation if Seoul complied with a U.N. resolution calling for the North to be punished for its October 9 nuclear test.
Political analysts say South Korea has been cautious in its response to the North's nuclear test because of its long-standing policy of engagement with the North. The analysts say Seoul is concerned that punitive action may only escalate tensions on the divided peninsula.
On Wednesday, however, U.S. Secretary of State Condoleezza Rice said Seoul's participation is crucial to the successful implementation of the U.N. resolution.
"It requires strong commitment by South Korea to the terms of that resolution, and any activities need to be seen in the light of making certain to implement that resolution," she said.
But experts say the impact of Seoul's sanctions may be small. Travel to the South by North Korean officials is already extremely limited. And Seoul says two joint-venture projects funded by the South - the Kaesong industrial park and the Mt. Kumgang tourist resort, both inside North Korea - will continue operations.
It is estimated that North Korea has earned almost a billion dollars from these two projects since 1998. The United States among others has criticized the projects, saying the North can use this money for its missile and nuclear weapons programs.
Hiro Katsumata, a Northeast Asia security expert at the Institute of Defense and Strategic Studies in Singapore, says Seoul's travel ban is a major departure from its accommodating approach to the North. But he says it may not make much difference if other key players, such as China and Russia, are reluctant to do their part.
"We have to understand that any sanction imposed against one country has to be multilateral because there can be many loopholes," he said. " If only Tokyo and Washington impose sanctions, then North Korea can find another way to facilitate transactions. Russia and China have not really imposed tough sanctions on North Korea."
While the U.S. and Japan have strongly backed full implementation of the U.N. sanctions, China, Russia and South Korea have not made clear how far they will go in complying.
For more than three years, these five countries have been trying to get Pyongyang to end its nuclear programs through dialogue. They have urged the North to return to negotiations it has boycotted since last November. But the North insists it will not do so unless separate sanctions, imposed by the U.S. to curb Pyongyang's alleged money laundering and counterfeiting, are lifted.