The leaders of Djibouti and Ethiopia will oversee the completion of a railway linking their two capitals on Thursday, with the ambition that the link might eventually extend across the continent to West Africa.

Djibouti's President Ismail Omar Guelleh and Ethiopia's Prime Minister Hailemariam Desalegn will attend the ceremonial laying of the last track in the 752-kilometre (481-mile) railway, financed and built by China, linking the port capital of Djibouti with landlocked Ethiopia's capital Addis Ababa.

The first scheduled train is expected to use the desert line in October, reducing transport time between the capitals to less than 10 hours, rather than the two days it currently takes for heavy goods vehicles using a congested mountain road.

"Some 1,500 trucks use the road every day between Djibouti and Ethiopia. In five years, this figure will rise to 8,000," said Abubaker Hadi, chairman of Djibouti's Port Authority. "This is not possible, this is why we need the railway."

With a capacity of 3,500 tonnes -- seven times the capacity of the old line at its peak -- the new electrified line will mainly be used for transporting goods to Africa's second-most populous nation.

Ethiopia's economy is growing fast, with almost 90 percent of its imports going through Djibouti. Both countries benefit from economic integration, with Ethiopia gaining access to the sea and Djibouti gaining access to Ethiopia's emerging market of 95 million people.

"Ethiopia is an important country for us," said Djibouti's Transport Minister Ahmed Moussa Hassan. "It is the main customer for our logistics facilities and this new railway line will strengthen trade."

The new line is in fact the resurrection of an old one, built in 1917 by the Franco-Ethiopian Railway Company, but decades later it fell into disrepair and only worked erratically. Trains would regularly derail and it could take as long as five days to make the journey between the two capital cities.

Some abandoned parts of the old line are still visible in Addis Ababa and in central Djibouti.

- Djibouti's ambitions -

Another new line linking Djibouti and the northern Ethiopian town of Mekele is also due to be built, but this is not the extent of the project's ambition.

Hadi says the railway is a step towards a trans-continental line reaching all the way to the Gulf of Guinea, in West Africa.

"We are already the gateway to Ethiopia. We intend to continue this railway line to South Sudan, the Central African Republic (CAR) and Cameroon to connect the Red Sea to the Atlantic Ocean," said Hadi.

Djibouti, the smallest state in the Horn of Africa, is embarking on large infrastructure projects, building six new ports and two airports in the hope of becoming the commercial hub of East Africa.

"Infrastructure is coming very late to Africa. It is impossible for a truck to cross the continent. To transport goods from the east coast to the west coast of Africa, it is necessary to circle the continent by boat," Hadi said of a sea voyage that can take more than three weeks.

A trans-Africa railway is feasible "in seven or eight years," he said, as long as conflicts in South Sudan and CAR come to an end.

Liu Xiaoyan, commercial director of the China Civil Engineering Construction Corporation, who is in charge of the Djibouti-Addis line, said his company is ready to continue the work.

"We want to show off Chinese technology to everyone, especially to Africa," he said, adding that it was also an opportunity to strengthen China's trade ties with Africa and its presence on the continent.