Kim You-geun, deputy director of Cheong Wa Dae's national security office, plans to hold a press briefing, it said.
Cheong Wa Dae initially planned to make an announcement on its plan to press ahead with the termination of the three-year-old pact.
But a related announcement was delayed amid news reports that it has convened a National Security Council session.
Japan's broadcaster NHK said Seoul has informed Tokyo of a decision not to end GSOMIA.
"(We) had lengthy discussions throughout the day and will soon announce the outcome," a Cheong Wa Dae official said earlier. The official did not rule out the possibility of "conditionally" postponing its expiry. (Yonhap)