SEOUL, South Korea — South Korea's president said Wednesday that urgent progress must be made next year in dismantling North Korea's atomic weapons program ahead of a key anniversary that could spur Pyongyang to bolster its nuclear capabilities.

President Lee Myung-bak said diplomats must quickly persuade the North to abandon its nuclear aspirations because Pyongyang is pushing to create a "powerful, prosperous nation" by 2012. The year is the 100th since the birth of Kim Il Sung, the revered guerrilla fighter-turned-political leader who founded the communist state in 1948 and the father of current leader Kim Jong Il.

That push could involve more aggressive behavior, and a South Korean Foreign Ministry-affiliated think tank, the Institute of Foreign Affairs and National Security, warned in a recent report that North Korea could be planning another nuclear test for next year.

The two Koreas are still technically at war because their 1950-53 Korean War ended with an armistice, not a peace treaty. Last month, the North shelled southern-held Yeonpyeong Island along the disputed sea border, killing four people, including two civilians, in its first assault on a civilian area since the war.

Six-nation talks on ending North Korea's nuclear weapons program have been stalled for nearly two years, with Washington and Seoul insisting that the North must make progress on past disarmament commitments before negotiations can resume. The North, chronically short of food and fuel, has previously used nuclear and missile tests, and violence, as ways to force the aid-for-disarmament talks and has recently said it's willing to return to negotiations.

The U.S. and South Korean hard-line stance, however, only strengthened last year after Pyongyang launched rockets and conducted its second nuclear test.

South Korea has reacted with shock and outrage this year to the North's alleged torpedoing of a southern warship in March, killing 46, and its deadly artillery barrage on the front-line island last month. North Korea denies the torpedo attack.

South Korea has recently indicated a willingness to hit back hard at the North should there be future attacks.

Worries about North Korea's nuclear program also deepened in November when the country revealed a uranium enrichment facility — which could give it a second way to make atomic bombs. North Korea is believed to have enough weaponized plutonium for at least a half-dozen atomic bombs.

President Lee called Wednesday for "big progress" in ridding the North of its nuclear programs next year. The stalled six-nation talks are the way to do that, Lee said while being briefed by officials about next year's foreign policy plans, according to the president's office.

Lee's office didn't immediately explain if the president was showing a new flexibility on resuming the nuclear talks involving the two Koreas, the United States, China, Russia and Japan.

A Foreign Ministry official, however, said that South Korea wants to see North Korea take "sincere" and "substantial" measures on nuclear disarmament before talks resume, speaking on condition of anonymity because of the sensitivity of the issue.

Foreign Minister Kim Sung-hwan later told reporters that chances for talks with North Korea on the nuclear issue remain open.