The message broadcast at 9:05 a.m. by the North's Korean Central TV and Korean Central Broadcasting Station marked the first verbal New Year's message by a North Korean leader in 19 years since North Korean founder and Kim's grandfather Kim Il-sung delivered one in 1994, the year of his death.
In the English script of the address, released later by the Korea Central News Agency (KCNA), Kim was quoted as urging the South Korean government to follow through on previous inter-Korean joint declarations.
"All the Korean compatriots in the North, South and abroad should launch a dynamic struggle to carry out to the letter the June 5 Joint Declaration and the October 4 Declaration," Kim said, referring to inter-Korean declarations signed under the South's two previous liberal administrations.
Kim called them "great reunification programs common to the nation in the new century and milestones for peace and prosperity," according to KCNA's English script.
Kim also urged his country and the South to prioritize "the great national cause of reunifying the country" and said "by holding fast to the ideals of independence, peace and friendship, we will, in the future too, strive to develop relations of friendship and cooperation with the countries that are friendly to our country."
The leader noted that the country's most important task is to "build an economic giant," calling for an increase in production, especially in the sectors of agriculture and light industry.
"Agriculture and light industry remain the major fronts for economic construction this year," Kim was quoted as saying. "All economic undertakings for this year should be geared to effecting a radical increase in production, and stabilizing and improving the people's living standards."
Praising the country's successful launch of a long-range rocket in December, he said, the launch helped "carry out the instruction of Kim Jong-il with credit and fully demonstrate the high level of space science and technology, and overall power of Juche Korea," referring to the country's guiding ideology.
On Dec. 12, the North fired off the rocket in what it said were efforts to put a satellite into orbit, but the outside world suspects it was a cover for testing rocket technology used for launching long-range missiles.
Since 1994, the country had released New Year's messages, deemed a major guideline for future policy direction, in the form of a joint editorial by its three main newspapers.
The rare voice message, analysts said, came as part of Kim's efforts to emulate the popular founder Kim Il-sung, who was known for friendliness and being one with the people.
Seoul's Unification Ministry in charge of inter-Korean relations said the North's address is largely consistent with the country's previous policy line of defending its military-first and socialist systems as well as revering its two late leaders.
The North's reference to its plan to continue to develop cutting-edge defense equipment denotes the country's willingness to further develop long-range missiles, the ministry said in a statement.
While South Korea's President-elect Park Geun-hye did not make any comment on the North's message, her aides said they would rather take a wait-and-see posture.
"It is not bad that North Korea appears to send a reconciliatory gesture, but it will not lead South Korea to come forward," said one aide who drew up Park's North Korea policy. "Seoul should and will watch further developments."
Another North Korea affairs expert working for Park said the North seems to send "a positive signal to the president-elect, but it remains to be seen how Pyongyang will act after the two sides work on pending issues in earnest after her inauguration."
Park will take office on Feb. 25.
The South Korean leader-in-waiting has hinted at a more flexible stance toward the North, vowing effort for an inter-Korean summit and the creation of exchange and cooperation centers in Seoul and Pyongyang.
But she at the same time has called for "strong security and trust-based diplomacy," indicating a reciprocal approach.
"The goal is to reach a balance between hard-line and overly dovish stances in setting Seoul's North Korea policy," Park said in a news conference in November ahead of the Dec. 19 vote.
A separate KCNA report said Kim Jong-un started the new year by watching a musical performance along with his wife, the North's state media said.
A New Year's performance was staged by the country's prestigious Moranbong Band in Pyongyang at midnight and "Kim Jong-un ... together with his wife, Ri Sol-ju, arrived at the venue of the performance," the (North) Korean Central News Agency (KCNA) said in an English-language dispatch.
High ranking officials, diplomatic envoys, scientists and other workers who contributed to the North's December long-range rocket launch were invited to the performance, according to the KCNA.
"Kim Jong-un and Ri Sol-ju shook hands with diplomatic envoys, representatives of international organizations and military attaches of foreign embassies here and their wives, offering congratulations and best wishes, and talked with them," the state news agency said.
The performance was comprised of "high praises of the undying feats" of the two late leaders of the North -- Kim Il-sung and Kim Jong-il -- and also staged "with the ardent reverence for Kim Jong-un who is ushering in the era of great prosperity," according to the KCNA report.
The year 2013 marks the young leader's second year at the helm of one of the world's most reclusive countries since his father Kim Jong-il died of a heart attack in December 2011.