"[Pyongyang] has devised a system whereby party organs report people's economic hardships on a daily basis. It has banned any gatherings related to drinking, singing and other entertainment and is strengthening control of outside information," the South Korean news agency Yonhap quotes the National Intelligence Agency (NIS) as saying during its briefing before the National Assembly's intelligence committee on Monday.
The move comes in an attempt to forestall the possible negative impact of the tightening of international sanctions on public sentiment, according to the agency.
Earlier in September, the UN Security Council adopted its latest Resolution on North Korea, 2375, which limited the country's crude oil and refined petroleum product imports, banned joint ventures, textile exports, natural gas condensate and liquid imports, and banned North Korean nationals from working abroad in other countries.
The punitive measures came in retaliation to the country's missile tests and the claims that it has tested a hydrogen bomb earlier in August.
According to the South Korean spy agency's Monday statement, it has been "closely watching the possibility of a new missile test by the North this year to escalate its threat to the United States under the guise of peaceful space development."
"But we forecast that depending upon North Korean leader Kim Jong-un's determination, a nuclear test is possible at any time," it said.
The agency also pointed out that "Tunnel 3 of the North's Punggye-ri test site is available for a test, while the North has recently resumed construction on Tunnel 4 with Tunnel 2 left unattended."