"When it comes to the anniversary, there has been no unusual signs in North Korea," Lee Duk-haeng, ministry spokesman, told a regular press briefing.

North Korea's state media called for showing allegiance to its leader Kim Jong-un ahead of the KPA anniversary. The country usually holds big military events or parades on anniversaries in which their final numbers end in a five or a zero.

Tensions between the United States and North Korea have heightened as Pyongyang has vowed to respond to Washington's possible preemptive strike with nuclear attacks.

North Korea unveiled what appeared to be three types of intercontinental ballistic missiles in a show of force at a military parade held on April 15, the 105th birthday of late state founder Kim Il-sung.

The US Navy strike group, including aircraft carrier Carl Vinson, is expected to arrive near the Korean Peninsula this week after conducting joint drills with Japanese destroyers in waters off the Philippines.

The Rodong Sinmun, the organ of the ruling Workers' Party of Korea, warned that its military is ready to "sink" the carrier "with a single strike" if needed. (Yonhap)