The North Korean leader has delivered a new year's message on state TV, the first such broadcast for 19 years.
Kim Jong-un, in power since 2011, spoke of the need to improve the economy and also to reunify the Koreas, warning that confrontation only led to war.
The speech came less than a month after the conservative Park Geun-hye was elected president of South Korea.
In 1994, Mr Kim's grandfather, Kim Il-sung, spoke on radio and TV. His son, Kim Jong-il rarely spoke in public.
In addition to Mr Kim's televised address, new year's messages were issued in the form of a joint editorial by North Korea's three main newspapers.
Kim Jong-un said 2013 would be a year of creations and changes, calling for a "radical turnabout" that would transform the impoverished, isolated state into an "economic giant" and raise living standards.
But while he said confrontation between the North and the South should be removed, Mr Kim stressed that military power remained a national priority.
"The military might of a country represents its national strength. Only when it builds up its military might in every way can it develop into a thriving country," he said.
The message coincides with UN Security Council discussions on how to punish Pyongyang for a recent long-range rocket launch.
Under Mr Kim's leadership, North Korea has conducted two long-range rocket launches - actions condemned by the US and Pyongyang's neighbours as banned tests of missile technology.
The launch in April failed, but December's attempt appears to have been a success, placing a satellite into orbit.
The US, Japan and South Korea are seeking a response in the UN Security Council, which banned North Korea from missile tests after nuclear tests in 2006 and 2009.
Kim Jong-un saw in the new year by watching a musical performance with his wife, North Korean state media reported.
North Korea's secretive 'first family'
North Korea thumbs nose at enemies
Key step in North Korea's missile ambitions
North Korea's missile programme