The two governments are expected to officially sign the General Security of Military Information Agreement (GSOMIA) as soon as this month after completing domestic procedures, said local reports quoting government sources.
The agreement was achieved after three rounds of working-level talks this month between officials of the two countries.
Japan and South Korea were close to signing the pact in 2012 but South Korea called off the deal at the last minute due to strong domestic opposition caused by negative sentiments over Japan's colonial rule of the Korean Peninsula before and during World War II.
The two sides resumed talks over the matter after a four-year lapse on Nov. 1, which has caused strong opposition from South Korean opposition parties.
South Korea's main opposition parties have threatened earlier in the day that they would "dismiss or impeach" the country's defense minister if the deal is signed.
Questions remain as to whether the pact could be effectively implemented even after it is signed, as South Korean President Park Geun-hye's government is currently in a political limbo due to a recent scandal, analysts here said.