North Korea warned the world Friday there would be no softening of its position toward South Korea's government after Kim Jong-il's death as Pyongyang strengthened his son and heir's authority with a new title: Great Leader. North Korea's powerful National Defense Commission said the country would never deal with South Korean President Lee Myung-bak, a conservative who stopped a no-strings-attached aid policy toward the North in 2008. The stern message also said North Korea was uniting around Kim Jong-un, referring to him for the first time with the title Great Leader — previously used for his father — in a clear message of continuity. It was the latest incremental step in a burgeoning personality cult around the son following the Dec. 17 death of Kim Jong-il. The younger Kim on Thursday was pronounced Supreme Leader of the ruling party, military and people at a massive public gathering on the final day of official mourning for his father. The top levels of government appear to have rallied around Kim Jong-un, who is in his late 20s, in the wake of his father's death. Still, given his inexperience and age, there are questions outside North Korea about his leadership of a nation engaged in delicate negotiations over its nuclear program and grappling with decades of economic hardship and chronic food shortages. “We declare solemnly and confidently that the foolish politicians around the world, including the puppet group in South Korea, should not expect any change from us,” the National Defense Commission said. “We will never deal with the traitor group of Lee Myung-bak.”