SEOUL, Dec 12: North Korea will not dismantle its nuclear programmes or improve ties with South Korea until questions about the South's nuclear experiments are clearly answered, Pyongyang said on Sunday.

The UN nuclear agency said in November South Korean scientists had enriched uranium to a level close to what would be used in an atomic weapon in 2000 and also extracted a small amount of bomb-grade plutonium in 1982.

"If the South Korean authorities are truly interested in the de-nuclearization of the Korean peninsula and a peaceful unification of the country, they should explain the truth about the criminal nuclear activities and immediately stop nuclear weapons development activities," the North's official newspaper Rodong Sinmun said.

"Without them, we cannot think about the de-nuclearization of the Korean peninsula, an improvement in the relations between the North and the South, or regional peace," Rodong Sinmun said in an editorial carried by the state's KCNA news agency.

The board of governors of the International Atomic Energy Agency has rebuked the South but did not refer the case to the UN Security Council, saying Seoul had cooperated well with agency inspections and the experiments likely did not continue.

North Korea has boycotted a planned fourth round of six-country talks aimed at dismantling its nuclear programmes since September. North and South Korea, the United States, Japan, Russia and China had met for three rounds of the slow-moving talks with little progress.

North Korea has demanded the United States drop a hostile policy against it before the talks can resume. The North has also boycotted ongoing dialogue with the South since August, angered by South Korea's airlift of 468 refugees from Vietnam.

South Korea hopes the beginning of production this week in a joint industrial district about 10 km north of the heavily fortified border between the two Koreas would help reopen dialogue. Seoul's top policymaker on the North, Unification Minister Chung Dong-young, is scheduled to attend the event on Wednesday. -Reuters