In this file photo, North Korea soldiers, left, stand at attention while being watched by South... 
(Kim Jae-Hwan/AFP/Getty Images)North Korea has declared it will seal its border with the South starting Dec. 1, after a recent escalation of tensions on the peninsula.
On Monday, Pyongyang notified Seoul that all tours to Gaesong, just 1.86 miles north of the demilitarized zone, will be closed. Travel permits for management personnel working at a South Korea-funded joint industrial complex, the icon of inter-Korean economic cooperation, are also to be reduced by half.
South Korean media has called the move another chapter in the impoverished North's history of brinksmanship. The aim, according to media reports, is to threaten the South's new conservative government and to draw the incoming U.S. administration into resuming nuclear talks.
Here's a Q&A primer on the ongoing story.
What's happening with international efforts to stop a nuclear North Korea?
Years of negotiations among six party talks – which include the two Koreas, the United States, China, Japan, and Russia – have been at a standstill. The next round is scheduled to resume in Beijing Dec. 8. Russia and North Korea have yet to confirm participation. Since reaching an agreement in September 2005 for Pyongyang to stop developing nuclear weapons in exchange for massive international aid, the talks have been on-and-off due to disagreements on details of verification protocol.
At the moment, the issue is whether North Korea should allow nuclear inspectors to take samples from the weapons-grade nuclear sites. The U.S. says it was part of the deal when it took North Korea off the terrorism blacklist last month, but Pyongyang disputes that. The communist North insists it will only allow field visits, document confirmation and interviews with technicians.
What's been happening to inter-Korean relations?
The two Koreas reached a historic agreement at the June 2000 summit to put behind confrontational hostility and work towards reconciliation and cooperation. Since then, human and economic exchanges have significantly increased, bringing a mood of hope for peace on the peninsula. Tourism projects, cultural exchanges, and business investment by the South have flourished despite international tensions over North Korea's nuclear program.
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