(CNN) -- North Korea threatened Tuesday to nullify the armistice agreement that ended the Korean War in 1953, citing U.S.-led international moves to slap new sanctions against it over its recent nuclear test, South Korea's Yonhap news agency reported.
The North's military said it will also cut off direct phone links with South Korea at the inter-Korean border village of Panmunjom, Yonhap said, citing North Korea's news outlet.
Both North and South Korea have technically been at war for decades. The 1950-53 civil war ended in a truce rather than a peace treaty.
There has been major concern in recent years among world powers over North Korea's nuclear aspirations.
The U.N. Security Council is expected to meet Tuesday to consider a proposed resolution to authorize more sanctions against North Korea in response to the secretive regime's controversial nuclear test last month.
The United States and China, a key North Korean ally, have been negotiating for weeks on the wording of the proposed resolution.
Pyongyang said the underground nuclear blast it conducted on February 12 was more powerful than its two previous detonations and used a smaller, lighter device, suggesting advances in its weapons program.
It was the first nuclear test the isolated state has carried out since its young leader, Kim Jong Un, inherited power in December 2011 after the death of his father, Kim Jong Il, who made building up North Korea's military strength the focus of his 17-year rule.
Like the regime's previous tests in 2006 and 2009, the move prompted widespread international condemnation, as well as a promise of tough action at the United Nations.
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