Kim Jong Un
North Korean leader Kim Jong Un (2nd L) and wife Ri Sol Ju (L) enjoy a joint performance given by the State Merited Chorus and the Moranbong Band celebrating the 70th founding anniversary of the Workers' Party of Korea in this undated photo released by North Korea's Korean Central News Agency (KCNA) in Pyongyang on October 19, 2015. REUTERS/KCNA

North Korea is getting ready for another nuclear test, according to South Korea's spy service, which also said that the North does not intend to go for the fourth nuclear test in the immediate future.

The National Intelligence Service’s assessment comes Tuesday in a closed-door meeting with lawmakers, the office of lawmaker Shin Kyung-min says. AP reported the South Korean spy agency had been monitoring activities at the main Nyongbyon nuclear complex in the North. The spy service has been using technical and human intelligence assets to monitor the activities, according to a memo provided by Shin's office.

North Korea said in September that its atomic fuel plants had been restarted and upgraded its fuel plants. The declaration caused speculations that the North might conduct another nuclear test explosion.

According to the South’s National Intelligence Service Yonhap, the North wants to conduct the nuclear test due to confrontational policies of the United States and its allies, USA Today reported. The first time the North conducted a nuclear test was in 2006. It also conducted nuclear tests in 2009 and in 2013.

The North conducted all its tests so far after launching long-range rockets. However, it earlier decided not to conduct a long-range rocket test. Therefore, speculations about the North conducting another nuclear test were subsided.

Meanwhile, hundreds of South Koreans met their families at a North Korean mountain resort Tuesday after having been separated from them during the 1950-53 Korean War. They did not manage to see their families for the last 60 years due to political tensions on the Korean Peninsula.