The NSC meeting will be held at 3 p.m., chaired by President Moon Jae-in's top security adviser and National Security Office chief Chung Eui-yong, according to Cheong Wa Dae, source from the Yonhap.
Thursday's meeting will involve all top security-related government officials, including Defense Minister Song Young-moo, Foreign Minister Kang Kyung-wha and National Intelligence Service chief Suh Hoon, it said.
A Cheong Wa Dae official said the meeting will mark a regular weekly meeting of the NSC.
Another official, however, said the top agenda for the meeting will make it a special session, also noting the ministers and the spy agency chief had often sent their deputies in their place in the past.
"It cannot but be a special meeting because of what it will discuss following what North Korea has said," the official said.
The meeting comes after the North's Korean People's Army again warned of a missile exercise that will include launching four ballistic missiles fired at the sea around the U.S.-controlled island of Guam in the Pacific.
In a statement carried by the North's official Korean Central News Agency, Gen. Kim Rak Gyom, commander of the Strategic Force of the Korean People's Army, said the country plans to launch four Hwasong-12 intermediate or long-range ballistic missiles that will "cross the sky above Shimane, Hiroshima and Koichi prefectures of Japan" and hit waters 30 to 40 kilometers away from Guam.
"The KPA Strategic Force will finally complete the plan until mid August and report it to the commander-in-chief of the DPRK nuclear force and wait for his order," the North Korean general said. DPRK stands for the North's official name, the Democratic People's Republic of Korea.
The renewed threat came one day after U.S. President Donald Trump told the communist state to stop making threats against the United States or be met by "fire and fury" the world has never seen before, prompting concerns here over a possible armed conflict.
Officials from the South Korean presidential office earlier insisted the North Korean threat may have been aimed at multiple objectives, including causing the kind of confusion and chaos currently seen in both South Korea and the United States, which in turn may weaken the alliance between the two, rather than signaling its actual or imminent armed provocation.
"I do not agree with the claim that the Korean Peninsula faces an imminent crisis," a Cheong Wa Dae official said while meeting reporters Wednesday.
"It is true the situation on the Korean Peninsula is becoming very serious due to North Korea's repeated provocations though many believe they are rather strategic provocations. We are working to fundamentally resolve the North Korean nuclear and missile issues at the earliest date possible, and are working with a belief that the possibility is very high," the official added, while speaking on condition of anonymity.