North and South Korea have held a symbolic ceremony to re-link cross border railways severed by war more than 50 years ago.
It will be some time before trains run between the two countries
Engineers from both sides tightened the screws on the railway tracks that will, it is hoped, eventually carry passenger trains between the two countries.
The event came a day before the third anniversary of an historic inter-Korean summit in which the then South Korean President Kim Dae-jung made a euphoric visit to the North Korean capital, Pyongyang.
Reconciliation has since stalled, and tension has heightened over North Korea's nuclear weapons programmes.
"Removing barbed-wire fences and mines, the nation's artery has been re-linked," said South Korea's chief delegate Cho Myong-kyun, speaking inside the four kilometre (2.5 mile) demilitarised zone that separates the two countries.
His North Korean counterpart Kim Byong-chil said: " "If we continue moving forward, with our hands linked together,
we will be able to tear down the barbed wire of division and achieve national unification."
The ceremony was supposed to have taken place in March, but was delayed because of the war in Iraq and the standoff over North Korea's nuclear ambitions.
Despite Saturday's ceremony it will be some time before trains run between the two Koreas, which were divided at the end of World War II.
The last train crossed the border shortly before the 1950-53 Korean War. The two countries remain technically at war, as there was a ceasefire but no formal treaty.
Two railways links are planned, but more work is needed.
Both sides have said they want to complete the restoration of the western line by September. This will run between Seoul and Pyongyang, and extend to North Korea's border with China.
If work goes to schedule, a rail link along the eastern coast will be ready by the end of the year.
But despite the progress on rail links, the BBC's Charles Scanlon in Seoul says North Korea's nuclear weapons programme is increasingly threatening reconciliation between the two countries.
On Monday, North Korea threatened to develop a "nuclear deterrent" unless the United States ends its "hostile policy".
It was the closest North Korea had come to publicly admitting that it was working on nuclear weapons.
Our correspondent says it has put a growing strain on South Korea's policy of reconciliation - what used to be known as the sunshine policy.
The United States and Japan have agreed on tougher measures - meaning sanctions - if the North continues to build nuclear warheads.
South Korean officials stress that dialogue is the only solution to the confrontation.