Kim on Thursday honoured the legacy of the party that he said had made "not a single mistake or error" in its 80-year history, leading the country on a path of ascent riding on the wisdom and strength of the people, KCNA state news agency reported on Friday.
"Today, we stand before the world as a mighty people with no obstacles we cannot overcome and no great achievement we cannot accomplish," he said at a speech at May Day stadium in Pyongyang attended by high-level foreign delegations, KCNA said.
Kim said North Korea had been pushing for the simultaneous development of nuclear weapons and the economy to cope with "growing nuclear war threats by the US imperialists".
"Our party and government are still coping with our adversaries' ferocious political and military moves of pressure by pursuing harder-line policies, holding fast to firm principles and employing brave, unflinching countermeasures," Kim said.
Kim also expressed confidence in overcoming difficulties and drastically improving the economy soon.
"I will surely turn this country into a more affluent and beautiful land and into the best socialist paradise in the world," Kim said.
The events come after Kim's visit to Beijing in September for China's 80th anniversary of World War II victory, standing with Chinese President Xi Jinping and Russian President Vladimir Putin at a massive military parade in his first public appearance on the multilateral diplomatic stage.
KCNA did not name the guests attending Thursday's events.
Chinese Premier Li Qiang, Vietnamese leader To Lam and Russian Security Council deputy chairman Dmitry Medvedev had arrived in Pyongyang to attend anniversary celebrations, state media had reported.
Mass games and art performances were held at the stadium with Kim accompanied by guests whom the crowd gathered greeted with cheers "that shook the capital's night sky", KCNA said.
State media made no mention of a large-scale military parade the country was expected to stage to mark the anniversary on Friday.
Kim held talks with China's Li, where they said the visit marked a "new chapter" in advancing the two countries' ties under their supreme leaders and pledged to expand strategic dialogue and high-level exchanges, KCNA said.
Kim separately received Vietnam's To Lam with an honour-guard welcome and held talks on advancing co-operation to meet global challenges, it said.
Medvedev held talks with senior North Korean officials and attended a reception held in his honour, KCNA said.
with AP
