South Korean President Lee Myung-bak says the opportunity exists for better ties with North Korea, but he warned the North to avoid any provocations.

In a nationally televised New Year's address Monday, Mr. Lee said the situation on the Korean peninsula is entering a new turning point.

“If North Korea comes to the table with sincerity, we can, together, open a new era on the Korean peninsula. We have to solve mutual trust issues through dialogue and take the road of mutual benefits and common prosperity.”

Mr. Lee's comments came as Kim Jong Un takes power in North Korea as Supreme Commander of the military and leader of the ruling party, after his father's death last month.

Pyongyang vowed Sunday in a New Year's message that it would bolster its military and defend Mr. Kim “until death.”

Mr. Lee warned that South Korea would sternly respond to any North Korean attack.

“…(A)s long as the possibility of North Korea's provocation remains, we will maintain a watertight defense posture. If provoked, we will strongly respond.”

North Korea has regularly criticized Mr. Lee since he took office in 2008 and ended a “no-strings-attached” aid policy toward the North.

Mr. Lee sought to link renewed aid transfers to progress in North Korea's nuclear disarmament.

“I hope this year will be a milestone in terms of North Korea's nuclear issue. As soon as North Korea suspends its nuclear activities, the six-party talks can 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.”

North Korea warned Friday there would be no softening of its position toward South Korea's government after Kim Jong Il's death.

Tensions between the two Koreas rose last year when Seoul accused Pyongyang of sinking a warship near the disputed sea border, known as the Northern Limit Line. Forty-six South Korean sailors were killed in the March 2010 attack.

Relations worsened after the North bombarded South Korea's Yeopyeong island in November 2010, killing four people.