SEOUL (AFP) - North Korea announced Friday it is scrapping agreements with South Korea on easing military tensions, accusing Seoul of pushing relations to the brink of war. The communist state said all political and military agreements would be nullified, including one covering their Yellow Sea border - the scene of bloody naval clashes in 1999 and 2002. The statement from the Committee for the Peaceful Reunification of Korea, a state body, heightened tensions after the North's army this month threatened an "all-out confrontational posture" against Seoul. South Korea stepped up border monitoring and vowed to respond firmly to any violation, but said no unusual activities have been detected. Seoul's unification ministry, which handles cross-border ties, expressed "deep regret." Raising tension between the two Koreas "is not desirable for settling peace on the Korean peninsula and in Northeast Asia as well as throughout the world," it said, renewing an offer of dialogue. "The confrontation between the north and the south in the political and military fields has been put to such extremes that inter-Korean relations have reached the brink of a war," the North's statement said. It blasted the conservative South Korean government of President Lee Myung-Bak for "ruthlessly scrapping" pacts reached at summits in 2000 and 2007. Lee, who took office a year ago, rolled back the "sunshine" engagement policy of his liberal predecessors and said he would review the summit pacts. "The group of traitors has already reduced all the agreements reached between the north and the south in the past to dead documents," the committee said in its statement carried by the official Korean Central News Agency. "Under such situation it is self-evident that there is no need for the DPRK (North Korea) to remain bound to those north-south agreements." Some analysts believe the North is trying to ensure it remains a diplomatic priority for the new administration of Barack Obama, and is also pressuring Seoul to reverse its tough stance. But others, like Paik Hak-Soon of the Sejong Institute think-tank, said armed clashes may break out soon. "This is something bad. The North is apparently paving the way for military provocations," Yoo Ho-Yeol, a professor at Korea University, told AFP. However, Baek Seung-Joo of the Korea Institute for Defence Analyses told AFP the statement aims at "heaping pressure on Lee Myung-Bak" and does not mean clashes are more likely. Meanwhile, the US said Friday that North Korea's "rhetoric is distinctly not helpful" after Pyongyang announced it scrapped agreements with South Korea on easing military tensions. "This type of rhetoric is distinctly not helpful but that's not going to deter us from continuing our efforts to achieve denuclearisation of the Korean peninsula," State Department spokesman Robert Wood told reporters.