"If the weather conditions are good tomorrow, (we) can do (the work)," the official said, as quoted by the Yonhap news agency.
Earlier in the week, a number of foreign journalists from the United States, the United Kingdom, Russia, and China arrived in Wonsan to cover the dismantling of the Punggye-ri site. They are expected to reach the nuclear test site on Thursday morning.
Eight South Korean reporters from News 1 agency and MBC broadcaster, whose trip was initially canceled, arrived in Wonsan on board of a government plane.
North Korean leader Kim Jong Un announced the shutdown of the Punggye-ri site during his summit with South Korean President Moon Jae-in in late April. However, Korean relations, which had improved dramatically since the beginning of the year, entered a new period of uncertainty as the United States and South Korea resumed military drills near North Korea's shores. Pyongyang has objected to the military exercises, which it sees as a threat.
The dismantlement of the nuclear site will take place between May 23-25.