The armistice that ended the 1950-53 Korean War remains valid despite North Korea’s declaration to have voided the agreement in a dispute with the United States, the United Nations said Monday. “The armistice agreement is still valid and in force,” said UN spokesman Martin Nesirky at UN headquarters in New York. “The terms of the armistice agreement do not allow either side unilaterally to free themselves from it,” Nesirky said, noting that UN Secretary General Ban Ki-moon has reiterated the “validity and importance of this critical agreement.” “This year marks the 60th anniversary of the 1953 armistice agreement of the Korean War,” Nesirky said. “The secretary general calls on the Democratic People’s Republic of Korea to continue to respect the terms of the armistice agreement, as it was approved by the General Assembly.”