JOIN USPresident Lee Myung-bak's appeal came as the rival Koreas negotiate on holding high-level defence talks, the first in more than three years, to ease months of hostility on the Korean peninsula that have raised fears of war.
Lee said the North must use the talks as a chance to show it is serious about improving ties with the outside world and changing its pattern of raising regional tensions with provocations and then seeking negotiations to wrest badly needed aid.
"North Korea has a good opportunity to change" its behaviour, Lee said during a panel discussion televised live. "I have high hopes for a change."
Asked whether a summit with North Korea's leader Kim was possible if the North demonstrates sincerity and that leads to bilateral and multilateral talks with North Korea,
Lee said, "Yes. I don't deny it. I'd hold a summit if necessary."
Tensions on the peninsula sharply rose after the North's artillery barrage killed four people on a front-line South Korean island in November. The bombardment came eight months after the deadly sinking of a South Korean warship blamed on Pyongyang.
The North has denied its involvement in the sinking, which killed 46 South Korean sailors.
Before last year's attacks, the two Koreas reportedly pushed for a summit but failed to agree due to differences over the impoverished North's demand for food aid.
Lee has said in the past that he was willing, in principle, to meet Kim at any time if that would help foster peace on the Korean peninsula, which has remained in a technical state of war since the three-year Korean War ended in a truce.