Lee Myung-Bak, in a speech to parliament, also offered to help alleviate the communist state's acute food shortages.

 

Lee's proposal for dialogue on summit pacts marked a clear departure from his initial tougher policy which led Pyongyang to term him a "traitor" and "US sycophant" and cut off contacts.

 

"Full dialogue between the two Koreas must resume," Lee said.

 

His government, he said, "is willing to engage in serious consultations on how to implement the inter-Korean agreements made so far," including summit pacts reached by his liberal predecessors in 2000 and 2007.

 

Lee has previously said he would study whether to carry out joint economic projects agreed with Pyongyang based on their feasibility and the cost to South Korea.

 

He had also linked major economic aid to the North to progress in scrapping its nuclear programmes.

 

The North responded angrily to Lee's harder line, which followed a decade-long "sunshine" engagement policy under liberal presidents. It has cut off all official contacts with the South.

 

Lee last weekend restated his willingness to meet the North's leader Kim Jong-Il "as many times as I can" for genuine dialogue to improve relations.

 

But the North said it was "preposterous" for Lee to make such a suggestion when he had ignored "important declarations" at previous summits.

 

The North has also rebuffed Seoul's offers of food aid despite serious food shortages this year.

 

Lee said Seoul "is ready to cooperate in efforts to help relieve the food shortage in the North as well as alleviate the pain of the North Korean people."

 

He stressed that the North's denuclearisation is his highest priority and welcomed "important and substantive progress" made in six-nation negotiations.

 

A new round of six-party talks was under way Friday in Beijing after the North delivered a declaration of its nuclear programmes and blew up part of its Yongbyon reactor.

 

"As the denuclearisation process progresses, substantial cooperation between the two Koreas will be rejuvenated. This will, in turn, open an age of the Korean peninsula, with both parts of the country thriving together," Lee said.

 

He also called for efforts to resolve the issue of South Korean prisoners of war, separated families and abductees.

 

"The South Korean POWs and the members of the first generation of separated families are now in their 70s and 80s. Therefore, it is the obligation of both Koreas to allow them to travel between the two sides," he said.

 

"These people should be allowed to meet with their long-separated family members and return to their home towns. This is a moral obligation."

 

Seoul says 485 South Koreans, mostly fishermen, were seized in the Cold War decades following the 1950-53 Korean conflict and more than 500 prisoners of war (POWs) were never sent home in 1953.

 

North Korea denies holding any South Koreans against their will and describes them as defectors, even though some have managed to escape and come South.

 

A programme of temporary family reunions has been suspended because of worsening relations. Official data shows that more than one in four of the South Koreans who sought reunions with relatives in North Korea died while awaiting an opportunity.

 

 

South Korean envoy Kim Sook (centre) at the opening ceremony of talks on North Korea's nuclear programme in Beijing.