North Korea praised Kim Jong Un's leadership in developing nuclear weapons, touted his political achievements, and unveiled new portraits and exhibitions to celebrate his 10 years in charge of the ruling Workers' Party of Korea (WPK).

Kim is considered to have assumed power when he was named supreme commander of the military after his father, Kim Jong Il, died in Dec. 2011.

Monday marks ten years since the younger Kim was elected as the top party and state leader. The Kim family has ruled the one-party state for its entire history.

In a speech at a national meeting on Sunday, Choe Ryong Hae, member of the Presidium of the Political Bureau of the WPK Central Committee and one of the most senior officials under Kim, praised the North Korean leader as "a gifted thinker and theoretician, outstanding statesman and peerlessly great commander."

The events started a week of commemorations that will also include the 110-year anniversary of the birth of Kim Il Sung, North Korea's founder and Kim Jong Un's grandfather, on Friday.

Commercial satellite imagery has shown North Korean troops practicing for a military parade that could be held this week. Analysts also say there are signs that North Korea could display its ICBMs at the event.

Last month North Korea set alarm bells ringing in Seoul, Tokyo and Washington by conducting a full ICBM test for the first time since 2017, ending a self-imposed moratorium on such tests

New construction has been spotted at North Korea's nuclear test site, raising concerns that it could soon explode a weapon for the first time since 2017. Last week North Korea said it opposes war but will not hesitate to use its nuclear weapons if it is attacked by South Korea.

Choe called Kim "a peerless patriot and a great defender of peace" for making North Korea "a full-fledged military power equipped with all powerful physical means of self-defence."

Under Kim North Korea conducted four of its six nuclear tests, and developed massive intercontinental ballistic missiles (ICBMs) that analysts believe may be capable of striking anywhere in the United States.

Despite facing unprecedented difficulties, Kim had opened up a new era for North Korea as a powerful socialist nation prospering and developing with self-sustenance and self-reliance, Choe said.

Kim has vowed to improve residents' lives and tried to boost North Korea's economy, but it suffered major contractions in recent years as it was battered by international sanctions, Covid-19 lockdown measures and bad weather. UN agencies have warned of possible humanitarian crises.

State media unveiled a rare new official portrait of Kim on Sunday, and reported that a Pyongyang museum had opened a new exhibition to showcase the achievements of his "immortal leadership".

"Ten years is a fine time for Kim to try and boost his cult of personality even higher," Colin Zwirko, an analytical correspondent with NK News, which monitors North Korea, said on Twitter.