Washington, Aug 22 (IANS): The Pentagon said on Saturday that its military leader pledged "unwavering commitment" of the US to South Korea's defence.

According to a Pentagon statement, US Chairman of the Joint Chiefs of Staff Army Gen. Martin E. Dempsey, called his South Korean counterpart Adm. Choi Yoon-Hee late on Friday night and reiterated the strength of the US-South Korea alliance, Xinhua reporetd.

The two military chiefs concurred they would watch North Korea's actions closely in the coming days and would ensure that the US and South Korea continue to work closely with each other to deter the North's "provocations and defuse tensions".

North and South Korea started high-level urgent contacts earlier Saturday in the truce village of Panmunjom to discuss the prevailing tense situation on the peninsula.

The meeting is the highest level inter-Korean contact since President Park took office in February 2013. It came amid escalated tensions caused by cross-border exchange of fire on Thursday over South Korea's propaganda broadcasts.

North Korea warned that unless South Korea stops propaganda broadcasts in frontline areas before 5 p.m., it will take military action. South Korea threatened stern retaliation against any further provocations.