North Korea has begun preparing festivities for the “Day of the Sun,” a holiday celebrating communist leader Kim Il-Sung. Satellite images suggest that among those festivities may be the nation’s sixth nuclear test, which would arrive at a particularly tempestuous time in the relationship between Pyongyang and its largest benefactor, China.

The satellite images in question appeared on the website 38 North this week, dedicated to monitoring North Korean nuclear sites for unusual activity. The outlet warned that the Punggye-ri Nuclear Test Site appeared “primed and ready” for such a nuclear test due to the amount of water and heat apparently coming out of the facility.

NBC News notes that the day before the 38 North report, Pyongyang “warned it would strike the U.S. mainland with nuclear weapons at any sign of aggression from Washington.” This, however, is not an unusual occurrence; last month, for example, North Korea threatened a nuclear strike on Manhattan.

The South Korean newswire service Yonhap reports that their sources within the South Korean military disagreed with the conclusions in the report, saying there had been “no unusual” activity at the site, or any other such nuclear site in the country to their knowledge.

“Another defense official here did not rule out the possibility that the unpredictable North will carry out a nuclear test without special indications spotted, given its past provocation,” the report added.

Another report at Voice of America suggested that evidence exists that a “nuclear device” is prepared to launch for Saturday, the “Day of the Sun.” North Korean nuclear officials have “apparently placed a nuclear device in a tunnel and it could be detonated Saturday AM Korea time.”

An official at the American National Security Council told Voice of America that the NSC “will be watching closely,” but did not elaborate.

North Korea has conducted five nuclear tests, the latest and largest in September. Pyongyang claimed that this test was of a hydrogen bomb – an “H-Bomb of Justice” – but nuclear experts disagreed, noting that the blast caused by the bomb was too small to have come from a pure fusion explosion. Experts contended the bomb was likely a fission-fusion hybrid.

Officials both in the United States and South Korea have been expecting an imminent nuclear test for months. Last month, an unnamed official told Fox News that a nuclear blast could occur before March was over, which ended up not happening.

The Korean Central News Agency (KCNA) – the state outlet – has published multiple articles praising Kim Il-Sung, who founded the dynasty Kim Jong-un now controls, in anticipation of Day of the Sun festivities.

“With the approach of the 105th birth anniversary of President Kim Il Sung, the father of socialist Korea, servicepersons and civilians in the DPRK recall with deep emotion his great life as the leader of people,” one article reads. “The President liberated the country from Japan’s colonial rule through the bloody anti-Japanese armed struggle to save the destiny of the nation.”

“The feats of Kim Il Sung who founded the Juche idea and built the people-centered socialist state on this land will shine forever,” the article concludes.

North Korea has also revealed the major event for which they corralled the nation’s media last night, and contrary to international suspicions, it was not a nuclear test, but the opening of a new residential area in Pyongyang. According to Yonhap, Kim Jong-un personally attended the unveiling of a new neighborhood in Pyongyang, billed as a “big and important event” to international media present.