By Dahee Lim
PAJU, South Korea (Reuters) - The head of South Korea's conservative ruling party made a rare visit to North Korea on Friday in the hope of improving soured relations between the rivals, but returned home with no breakthrough.
At the same time, private groups sent a 12-truck convoy of food supplies to the impoverished North to help residents hit by floods.
Grand National Party chief Hong Joon-pyo travelled to Kaesong, an industrial park in the North run by both sides, to try to end a more than three-year freeze in ties.
He met no officials during a stay of less than six hours, but offered to promote a policy of "flexibility" with the North.
"The Kaesong project is a key point on the road to an economic joint community and a peace community," he told reporters on his return. "We will therefore discuss with the government a more flexible approach to policy (on the North)."
President Lee Myung-bak cut off nearly all commercial ties and dialogue after an international team of experts led by the South's military concluded a North Korean torpedo sank one of its navy ships last year, killing 46 sailors.
North Korea denies it was involved.
Tensions rose to their highest level since the 1950-53 war after an artillery attack by the North on a South Korean island.
Lee's government has recently engaged the North in dialogue over stalled international talks to end Pyongyang's nuclear arms program. But it has been reluctant to hold bilateral talks and maintains a ban on shipment of state food aid to the North.
Hong and the GNP face an uphill battle to retain a majority in a parliamentary election next year, where better ties with the North will be a campaign issue among voters separated from family members since the war. The party has pledged to try to mend ties and restore humanitarian aid.
The convoy, carrying flour, medicine, other food items and clothes, was donated by a group of NGOs. It crossed the armed border on Friday with plans for deliveries to schools and child care centers in the stricken agricultural central region.
The Kaesong industrial complex has hosted more than 120 small South Korean companies operating factories to make household goods like pots, cosmetics cases and clothes, using cheap North Korean labor and land.
(Writing by Jack Kim; Editing by Ed Lane)