Seoul: South and North Korea set up a military hotline on September 24 across the world's last Cold War frontier to avoid a possible conflict over demining work for a landmark inter-Korean path.

The first inter-Korean hotline was established between South and North Korean engineering squads, which began clearing the buffer zone, on September 19, the South's Defence ministry said.

"The line was hooked but both sides have yet to speak through it," a ministry official said.

"The North told us that technical problems are delaying an immediate conversation between the two sides," he added.

The two Koreas, still technically at war, have agreed to link up two railways and roads cut for half-a-Century, one on the West coast and a second line on the East coast.

The demining operation is under way simultaneously at the two border sites in the demilitarised zone (DMZ), which divides the Korean peninsula.

The DMZ is a four-kilometre (2.4-mile) wide buffer zone that runs 250 kilometres (155 miles) from sea to sea. It is uninhabited but strewn with millions of landmines.

South and North Korean officials have heralded the establishment of transport links as an historic breakthrough in efforts to unite the divided Korean peninsula.

The establishment of cross-border communication lines followed a Construction and Transportation Ministry report on North Korea's outdated railway facilities.

The report suggested the planned opening of railways from Seoul up to the North's border with China and Russia could be delayed.

Tracks, tunnels and other railroad facilities in North Korea are so dilapidated they need complete repair or replacement, the ministry said, adding most of the North's railway bridges need complete replacement.

South Korea has agreed to provide 50 billion Won ($ 40.8 million) worth of construction materials and equipment necessary for the reconnection of cross-border railways and roads.

Analysts say, however, that the North may ask for more money to repair its railway facilities.

South Korea hopes to complete the reconnection of the West line by the end of the year and the East line next spring.

The railway project was a key point of a new peace accord signed last month when the two Koreas resumed dialogue for the first time in 20 months.

Rail links were severed prior to the outbreak of the Korean War. Workers will link a 27-kilometre (16.7 mile) severed section in the East and a 14.2-kilometre (8.8 mile) section in the West.