SEOUL - Defense minister of Republic of Korea (ROK) Kim Kwan-jin said Tuesday he is having second thoughts about lighting up Christmas tree-shaped towers along the border, a move that might upset the Democratic People's Republic of Korea (DPRK).

"We will reconsider the plan because it runs counter to the current situation," Kim told the parliamentary defense committee earlier Tuesday, referring to the plan to light Christmas tree - shaped towers along the land border.

The DPRK considers the towers illuminated by small light bulbs a form of "psychological warfare", and recently warned of " unpredictable situation" if its former wartime enemy goes ahead with the original plan to light them up on Friday.

The defense minister's decision to reconsider the plan came a day after the DPRK state media announced its leader Kim Jong-il died on Saturday of a heart failure.

ROK's military immediately put all military units on heightened alert and intensified border surveillance, but stopped raising the Watchcon surveillance status to refrain from creating "an unnecessary sense of crisis".

Last year, ROK lit up a giant Christmas tree-shaped tower on the top of the Aegibong hill in the city of Gimpo.

The annual ritual of lighting up the symbolic tree tower was suspended in 2003 as the two Koreas, amid a growing conciliatory mood, agreed to stop propaganda war.