"A very, very few soldiers have gone out there for what we call recce, or reconaissance," Colonel Chukwuemeka Onwuamaegbu told AFP.
"They will obtain information about what the environment will be like."
The spokesperson was unsure of the precise number of troops involved, but thought it might be a few as three.
Nigeria is expected to provide the largest contingent of peacekeepers in a 1 500-strong force set up by the Economic Community of West African States (Ecowas). The force may eventually be joined by US troops.
A dozen Ecowas officers arrived in Liberia on Saturday to prepare the way for the mission, which was conceived as a force to police a ceasefire but now faces the prospect of intervening in an ongoing conflict.
It was not clear whether the Nigerian party was included in this group, which was cheered by anxious Liberians who initially mistook it for US Marines.
Rebel fighters pushed over a strategic bridge on the outskirts of the Liberian capital Monrovia during heavy fighting Saturday against troops loyal to warlord-turned-president Charles Taylor.
Nigeria has offered Taylor asylum if he agrees to step down and allow a shaky peace process to get back underway. - Sapa-AFP