North Korean leader Kim Jong-un has opened a building project close to Mount Paektu, a symbol of the Korean nation and officially the birthplace of his father and predecessor, state media reported Tuesday.
The ceremony was held in snowy scenes before thousands of soldiers and civilians, and portrayed as a demonstration of the resilience of the North, which is subject to international sanctions imposed over its nuclear weapons and missile programmes.
It comes with time running out on Pyongyang's demand for the US to offer it fresh concessions by the end of the year, and ahead of Mr Kim's New Year speech on January 1, a key political set-piece in the isolated country.
Mr Kim donned a black leather trench coat and gloves for the opening, and cut a red ribbon in front of a statue of his father Kim Jong-il.
Winter already has North Korea's far north firmly in its grip, and icicles hung from buildings, Korean Central Television footage showed. The largely empty streets are covered in snow.
Banners proclaimed: "Long live the great leader of the force of our party and country, comrade Kim Jong-un."
Mr Kim had "worked heart and soul to turn Samjiyon County, the sacred place of the revolution, into the utopia town under socialism", the official KCNA news agency said.
The Korean people were, it said, "advancing along the straight road chosen by themselves without any vacillation despite the worst trials".
Nuclear negotiations with the US have been deadlocked since the Hanoi summit broke up in February, and Pyongyang has issued increasingly assertive comments in recent weeks as its deadline approaches.
"What gift the US receives for Christmas depends entirely on the US decision," Vice Foreign Minister Ri Thae-song said.
Pyongyang has poured huge resources into rebuilding Samjiyon, the closest town to Mount Paektu, a dormant volcano that straddles the border with China.
Mr Kim is closely associated with the scheme and has visited several times, reportedly riding a white horse to the mountain's summit in October.
The vast project includes a museum of revolutionary activities, a winter sports training complex, processing plants for blueberries and potatoes, and 10,000 apartments.
Thousands of workers swarmed over the site during construction, many of them soldiers. Much of the North Korean army is used for building.
Students have been sent to work on the scheme during university holidays, while diplomats say children have also gone there.
According to North Korean propaganda, Kim Jong-il was born at the nearby Mount Paektu Secret Camp where his own father, Kim Il-sung was fighting the Japanese,.
Independent historians and Soviet records, however, say he was born in Russia, where North Korea's founder was in exile.
The official story plays a central role in Pyongyang's teachings about the Kim family, who have led the country for three generations.
Every year,100,000 or more students and workers are taken on study trips to the area.