The United Nations command in Korea is denying Pyongyang's allegation that U.S. and South Korean forces introduced "heavy weapons" into the demilitarized zone last Saturday.
North Korea's army is threatening retaliation, if the unspecified weaponry is not removed from the DMZ. The allied forces say the allegation made by Pyongyang is not true.
Both sides are allowed to have only pistols and rifles in the truce area separating the two Korea's.
"United Nations Command continues to abide by the 1953 Korean Armistice Agreement and did not move heavy weapons into Panmunjom on 26th June," said David Oten, a spokesman for U.S. Forces Korea.
The American military spokesman, citing the U.N. Command's response Tuesday to the charge, says North Korea should bring its concern to the appropriate forum - the general officer military talks at Panmunjom.
"The Armistice Agreement and the Supplemental Agreements to it provide a forum to resolve these types of misperceptions and allow for direct engagement between representatives from the [North] Korean Peoples Army and the United Nations Command," said Oten. "The two sides have met at the truce village on many occasions in the past to resolve security concerns and Armistice related issues."
The North Korean force warns that, if the alleged heavy weapons are not removed, then it will take "strong military counter-measures".
North Korea is also objecting to planned joint maritime exercises by the United States and South Korea. Those military drills are expected to be held in July in the Yellow Sea.
The exercise is seen as part of the unified response to the sinking of a South Korean coastal warship, three months ago. An international investigation concluded that the Cheonan was hit by a North Korean torpedo, which Pyongyang denies.
A North Korean media commentary calls the planned naval drill provocative and dangerous, warning that an accidental clash at sea could result in all-out war.
The three-year Korean War started 60 years ago, this month. A peace treaty has never been signed.