SEOUL, South Korea (AP) -- South Korea's president opened the door Monday to possible nuclear talks with North Korea and warned the neighboring country to avoid any provocations, saying the Korean peninsula is at a crucial turning point.
Lee Myung-bak's comments in a nationally televised speech come as the young son of the late Kim Jong Il takes power in North Korea as Supreme Commander of the military and ruling party leader after Kim's death last month. The North vowed Sunday in a New Year's message that it would bolster its military and defend the son, Kim Jong Un, "unto death."
"The situation on the Korean peninsula is now entering a new turning point," Lee said. "But there should be a new opportunity amid changes and uncertainty."
Lee warned that South Korea would sternly respond to any North Korean provocation. In 2010, 50 South Koreans died in attacks blamed on the North, though the Koreas have met in recent months for preliminary nuclear discussions.
North Korea, which has tested two atomic devices since 2006, has said it wants to return to long-stalled six-nation talks on halting its nuclear weapons program in return for aid. Washington and Seoul, however, have insisted that the North first show progress on past disarmament commitments.
If North Korea halts its continuing nuclear activities, Lee said in his speech, negotiations could resume.
"We are ready to resolve security concerns on the Korean peninsula and provide assistance to revive North Korea's economy through agreements in the six-nation talks," Lee said.
North Korea, however, has so far taken a hard line toward the South. It warned last week that there would be no softening of its position toward South Korea's government after Kim Jong Il's death. North Korea's powerful National Defense Commission said the country would never deal with Lee.
On Monday, Pyongyang accused Lee of plotting to shake up the North by temporarily placing his troops on high alert after Kim Jong Il's death. The North's main Rodong Sinmun newspaper said in a commentary carried by the official Korean Central News Agency that Lee must "kneel down and apologize" for his acts.
North Korea has regularly criticized Lee since he took office in 2008 and ended a no-strings-attached aid policy toward the North. Lee sought to link aid to progress in North Korea's nuclear disarmament.
The six-nation nuclear talks involve the two Koreas, the United States, China, Russia and Japan.
The Korean peninsula remains technically in a state of conflict because the 1950-53 Korean War ended in a truce, not a peace treaty.
North Korea's New Year's message, however, didn't include the country's routine harsh criticism of the United States and avoided the country's nuclear ambitions, a suggestion that the North may be willing to continue talks with Washington to win food aid.
This year is a crucial one for North Korea as it tries to build a "great, prosperous and powerful nation" befitting the April 2012 centenary of the birth of national founder Kim Il Sung, the new leader's grandfather.
In the North Korean capital, Pyongyang, New Year's Day was cold, snowy and gray, with splashes of bright color provided by flags, lanterns and banners reading "Happy New Year" that decorated the streets. Coming just days after the official mourning period for Kim Jong Il ended, the celebration was muted, unlike past years when cheerful people in their best holiday clothes thronged the streets.
Kim Jong Un, meanwhile, spent part of the day visiting a tank division, state media said, in what was apparently his first reported military field inspection since his father's death. Kim Jong Il regularly visited military units, factories and farms across the country, and his son's trip provided further evidence of the North's intention to link him closely with the military.