North Korea threatened Wednesday to stage a pre-emptive nuclear strike against the United States upon Washington's miscalculation ahead of the 64th anniversary of the signing of the armistice that ended the 1950-53 Korean War.

Pak Yong-sik, the minister of North Korea's armed forces, made the remark during his speech in a meeting to mark the anniversary slated for Thursday.

"If enemies misunderstand our strategic status and stick to options of staging a pre-emptive nuclear attack against us, we will launch a nuclear attack on America's heart as the most relentless punishment without warning or prior notice," Pak was quoted as saying by the Korean Central News Agency.

The North's warning came amid speculation that North Korea may be preparing to carry out another missile test launch around the anniversary.

Transporter vehicles carrying equipment for the firing of a ballistic missile were seen arriving in Kusong of the country's northwestern province, CNN reported Wednesday, citing an unnamed US defense official.

The armistice was signed on July 27, 1953, leaving South and North Korea technically in a state of war. The North has designated the date as Victory Day to celebrate what it claims is its victory against the US during the war.

North Korea may respond to South Korea's latest offer for inter-Korean talks with a possible missile launch following its test-firing of an intercontinental ballistic missile on July 4.

South Korea earlier proposed holding military talks last Friday to end hostile acts along the tense inter-Korean border on the occasion of the anniversary. But the North has not shown any response to Seoul's proposal.

North Korea has been advancing its nuclear and missile programs with the goal of developing an ICBM capable of hitting the US mainland.

The United Nations Security Council is working on a new sanctions resolution over the North's latest missile test. Pyongyang has threatened to take "corresponding measures" if the UNSC slaps new punitive actions against it.

The North's possible provocation could dampen President Moon Jae-in's push for engagement with the North at a time when the US is trying to tighten sanctions on Pyongyang.

South Korea's unification ministry said that there is no deadline for Seoul's dialogue offer.

"The government will wait for North Korea's reply in a calm manner," Baik Tae-hyun, ministry spokesman, told a regular press briefing. (Yonhap)