SEOUL: A North Korean documentary broadcast on Tuesday showed a limping leader Kim Jong Un as he tackles the impoverished country's "worst-ever hardships" amid the coronavirus pandemic and sanctions over its weapons programmes.

Titled "The Great Year of Victory, 2021", the 110-minute film chronicled a series of achievements throughout the year including on missile development, construction and efforts to beat the pandemic.

The narrator repeatedly lauded such projects as signs of "victory" led by a noticeably thinner Kim, in line with previous such documentaries used by state media to craft a semi-divine personality cult around him.

The film did not elaborate on the hardships but reclusive North Korea, unlike rich, democratic South Korea, faces deepening food shortages amid the sanctions, drought and floods, according to U.N. agencies.

North Korea has not confirmed any COVID-19 cases, but has closed its borders. It has been steadily developing its weapons systems amid an impasse over talks aimed at dismantling its nuclear and ballistic missile arsenals in return for relief from U.N. and U.S. sanctions.

At one point in the film, Kim was seen struggling to walk down makeshift stairs during a visit to a rainy construction site.

"This video showed his motherly side where he completely dedicated his own body to realise people's dreams," the narrator said.

The film did not directly refer to Kim's weight loss, but he has appeared increasingly thinner in recent state media photos.

In June, state media said North Koreans were "heartbroken" to see an "emaciated" Kim, in a rare such dispatch, after he reappeared following absence from the public eye of almost a month.

International media, intelligence agencies and experts closely watch Kim's health due to his tight grip on power and the uncertainty over succession plans.

The documentary also showed Kim watching the sunrise alone while riding a white horse on a beach. On another ride, he was seen with military officials including Pak Jong Chon, chief of the General Staff of the Korean People's Army, followed by a clip of tanks staging live-fire drills.

The film included rare images of a new 80-storey skyscraper and a large apartment district, as well as some clips and images of a defence expo in October and previous missile tests.

In December, Kim said the ruling party had some success in implementing a five-year economic plan he unveiled early last year, but warned of a "very giant struggle" this year, citing the pandemic and economic difficulties.