The address by Mr Kim, who took over power after his father, Kim Jong-il, died in 2011, appeared to take the place of the policy-setting New Year editorial published in leading state newspapers.
But North Korea has offered olive branches before and Mr Kim's speech does not necessarily signify a change in tack from a country which vilifies the US and South Korea at every chance it gets.
Impoverished North Korea raised tensions in the region by launching a long-range rocket in December that it said was aimed at putting a scientific satellite in orbit, drawing international condemnation. North Korea is banned from testing missile or nuclear technology under UN sanctions imposed after its 2006 and 2009 nuclear weapons tests.
The New Year address was the first in 19 years by a North Korean leader after the death of Kim Il-sung, Kim Jong-un's grandfather. Kim Jong-il rarely spoke in public.