(http://msnbcmedia.msn.com/j/MSNBC/Components/Photo/_new/130125-nk-sk-border-5a.photoblog600.jpg)Jung Yeon-Je / AFP - Getty ImagesSouth Korean soldiers patrol along a fence in Paju near the Demilitarized Zone dividing the two Koreas Friday.By Jack Kim, ReutersSEOUL -- North Korea threatened Friday to attack rival South Korea if Seoul joined a new round of tightened U.N. sanctions, saying it would regard this as "a declaration of war."
The reclusive North has this week declared a boycott of all dialogue aimed at ending its nuclear program and vowed to conduct more rocket and nuclear tests after the U.N. Security Council censured it for a December long-range missile launch.
On Thursday, Washington unveiled more of its own economic restrictions following Pyongyang's rocket launch last month.
Friday brought a third straight day of fiery rhetoric from the isolated communist state, this time directed against South Korea.
"'Sanctions' mean a war and a declaration of war against us," the North said.
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