The congress, which opened on Thursday, is the nation's biggest political event held every five years to review performances, set new policy goals and which can bring changes in leadership roles beneath the supreme commander Kim.
In his opening speech, Kim said North Korea had made "significant accomplishments" over the past five years in politics, economy, defence, culture and diplomacy, enhancing its self-reliance.
For the outside world, North Korea has brought a "big change" in relations with other countries and the global geopolitical landscape, he said.
Kim did not mention relations with the United States or neighbouring South Korea in his speech, and did not refer to his country's efforts to develop a stockpile of nuclear weapons.
At the meeting, attended by 5000 members of the ruling Workers' Party, new goals and plans in various sectors for the next five years were submitted, KCNA reported.
The congress comes after a weeks-long build-up during which Kim flaunted his military capabilities and toured major industrial and housing projects to tout his claimed achievements over the past five years.
North Korea is expected to showcase military capabilities at a parade and weapons development goals as part of the meeting.
Analysts are also monitoring whether Kim would be given the title of "president" and if his teenage daughter, Ju Ae, makes an appearance or receives some form of official post.
There has been increasing speculation among analysts and from South Korea's spy agency that Kim is grooming Ju Ae to succeed him.
When the previous Eighth Congress was convened, the circumstances surrounding North Korea were "extremely challenging", Kim said, citing natural disasters and an international health crisis, apparently referring to the COVID-19 pandemic.
The country's economy and industries were running on old practices, Kim said.
North Korea's economy suffered its biggest contraction in 23 years in 2020 as it was battered by continued UN sanctions, COVID-19 lockdown measures and bad weather, South Korea's central bank has said.
But more recently there have been signs of recovery and the economy grew 3.7 per cent in 2024, the fastest annual pace of growth in eight years, backed by expanded economic ties with Russia, according to estimates by the Bank of Korea.
"Everything has changed fundamentally for the past five years," Kim said.
He pushed the party to make efforts to change the nation in all sectors for economic growth and improving people's livelihoods "as soon as possible".
Earlier this week, Kim marked the completion of 10,000 new houses built in Pyongyang, which achieved the goal of building 50,000 homes set during the Eighth Congress.
It is unclear for how long the gathering will run, but the Seventh Congress lasted four days and the Eighth Congress ran for eight days.
With AP
