The reports from Russian news agencies need to be corroborated, and the government is "assessing the implications," Seoul's Foreign Ministry spokesman Cho Joon-hyuk said Thursday.
Cho added that in accordance with the government's findings, a response would be determined.
According to Asaad Al-Zoubi, the head of the Syrian opposition's High Negotiations Committee delegation, North Korea has committed troops to the Syrian civil war.
Al-Zoubi had said the two units are called Chalma-1 and Chalma-2.
The Syrian delegate had provided the information as he attended peace talks at the United Nations European headquarters in Geneva.
North Korean troops are "fatally dangerous," Al-Zoubi had said.
The civil war has continued for five years, and the opposition and the Assad regime are at odds regarding the details of a peace negotiation.
But Pyongyang maintains friendly ties with the dictatorship in Damascus, and Russia has supported Assad's rule.
While Seoul officials remain skeptical of the claims, experts said it is highly possible North Korea is militarily involved in the protracted conflict in the Middle East.
Experts have said North Korea co-developed weapons with Syria, beginning in the late 1990s, South Korean newspaper Maeil Business reported.
South Korea press reported a North Korea ship carrying 1,400 pistols, 30,000 rounds of ammunition and hundreds of gas masks was seized by Turkish authorities in March 2013. At the time, the ship was headed for Syria.
North Korea has also trained various armies in Africa and the Middle East. A 2014 report from a United Nations panel of experts concluded North Korea had signed an agreement with the Ugandan government to train its police force.
Other experts have said North Korea dispatches troops to earn foreign currency abroad.