North Korea's Chollima-1 rocket, carrying the regime's inaugural military reconnaissance satellite, takes off from a site in Dongchang-ri, North Pyongan Province, on May 31, in this photo released the following day by the North's official Korean Central News Agency. Yonhap

South Korea's presidential office suggested Tuesday that a 2018 inter-Korean military tension reduction agreement could be suspended in the event North Korea goes ahead with its planned space rocket launch.

The remark by a senior presidential official came after North Korea reportedly notified Japan of its plan to launch a space rocket between Wednesday and Dec. 1, in what would likely be its third attempt to put a military spy satellite into orbit.

"If you read carefully the Development of Inter-Korean Relations Act, any discussions between the South and the North can be suspended in part or in whole in the event of a critical cause, including those related to national security," the official told reporters in London where South Korean President Yoon Suk Yeol is on a four-day state visit.

"We can take action in line with that clause ... and because the type of provocation North Korea will engage in has not been decided yet, depending on the type and scale of provocation, we will have to decide the scope and details of the necessary steps regarding the Sept. 19 agreement," he added.

The Comprehensive Military Agreement, signed on Sept. 19, 2018, under the previous liberal administration of President Moon Jae-in, calls for halting all hostile military activity between the Koreas, setting up maritime buffer zones and turning the Demilitarized Zone into a peace zone, among other things.

The presidential official noted North Korea has "unilaterally and consistently violated" the agreement for a long time, posing limitations for South Korea's defense posture.

The official assured that a system is in place to ensure Yoon can be briefed immediately in the event North Korea carries out the launch even during his busy schedule in London. (Yonhap)