Australia's prime minister said North Korea must be ready to compromise on military issues, including its nuclear program, or there's no point in restarting stalled talks.

Australian Prime Minister Julia Gillard made the comments during a two-day visit to South Korea that included attending a Korean War memorial service to honor Australians who fought North Korean soldiers in the three-year war.

Fighting stopped after a cease-fire was agreed in 1953 that effectively drew a line across the Korean Peninsula creating the two countries, which are technically still at war.

''There's no point just saying 'sit down and talk,' if the talks are not going to achieve anything,'' Gillard said at the memorial service.

On the weekend, she said the Korean War was ''to defend the young (southern) republic against North Korean aggression."

She commemorated the 60th anniversary of the Battle of Kapyong, northeast of Seoul, during which Australian and Canadian forces fought a Chinese division to a standstill. She also attended a memorial service in Seoul and laid a wreath at the national war memorial.

Gillard went to the demilitarized zone that separates the two Koreas and visited international troops stationed along the border.

Inside the building known as T2, she walked across a room that straddles the border and is also where meetings between the military from the two Koreas and their allies take place. She told journalists, "It's an unusual experience, isn't it?''

Gillard's visit comes as Pyongyang has made overtures that it wants to restart the six-nation talks to denuclearize North Korea. The talks, which involve the two Koreas, Japan, Russia, China and the United States, were abruptly halted in April 2009, shortly before North Korea conducted a test nuclear explosion.

North Korea has maintained its nuclear development is for peaceful and defensive purposes, as well as maintained the number of its nuclear facilities as a secret.

North Korea also is reportedly interested in discussing food aid after punishing winter weather that followed last summer's major foods.

But political and military tensions between the two Koreas increased in the past year.

Seoul is seeking an apology from Pyongyang for North Korea's unprovoked shelling of a South Korean island in the Yellow Sea -- several miles from the North's mainland and the fatal sinking of a South Korean patrol boat.

Dozens of houses and several military buildings were damaged in the artillery attack on Yeonpyeong that killed two South Korean marines and two civilians and injured at least 20 people. South Korean forces returned fire but there were no known causalities.

In March, South Korea blamed North Korea for sinking of the 1,200-ton South Korean patrol boat Cheonan and the loss of 46 sailors. North Korea repeatedly denied it had sunk the vessel despite an international investigating team that said it found strong evidence that the Cheonan, which split in half, was hit by a torpedo of North Korean manufacture.

''I think negotiations will be only possible once North Korea has displayed a clear position regarding its provocations with the Cheonan warship incident and the artillery attacks on Yeonpyeong Island,'' South Korean Minister of Defense Kim Kwan-jin told the Australian newspaper The Age during the memorial service to Australian soldiers.

Gillard left Seoul for Beijing as part of a northern Asia tour.

Meanwhile, a group of former world leaders, including former U.S. President Jimmy Carter, are visiting North Korea as part of a private visit to talk to officials in Pyongyang about their nuclear program, as well as gather information about food shortages.

The group, known as The Elders, includes Mary Robinson, former president of Ireland, former Finnish President Martti Ahtisaari and former head of the World Health Organization, Gro Harlem Brundtland. Their stops include Beijing and Seoul.